Why the Cheapest Duplex Quote Can Cost Investors More

When it comes to duplex investing, the cheapest price upfront is rarely the cheapest in the end.

It is easy to compare builders based on the sticker price and select the lowest number. However, that initial figure often does not tell the whole story.

A low base price can quickly increase when planning contributions, site costs, provisional sums and essential finishes are added during the project.

For investors, the most important question is not simply which builder has the lowest quote.

It is whether the price is transparent, complete and reliable from the beginning.

Look for Genuine Pricing Transparency

The first thing investors should look for is a company that is open and transparent about its pricing.

It is common for builders to present a low base price and then add upgrade after upgrade once the project is underway.

At RPG, we take the opposite approach.

We provide customers with a fixed price that we hold from the start. This means the financial risk sits with us, rather than being passed back to the investor later.

That is the way it should be.

The Costs That Can Be Left Out

Several major expenses may not be included in an initial duplex development quote.

Planning Contributions

As an example – in some areas of the Shoalhaven, planning contributions can be around $55,000.

When this amount has not been included or clearly explained at the beginning, it can significantly change the investment numbers.

Unexpected Groundworks

Another example: During a recent RPG duplex development, we unexpectedly encountered rock that cost approximately $20,000 to remove.

Because the project had a fixed price, RPG absorbed the additional cost.

RPG customers are not asked to find another $20,000 halfway through the investment.

Provisional Sums and Prime Cost Items

Provisional sums and prime cost items are allowances rather than guaranteed final costs.

They may make an initial quote look attractive, but these amounts can increase once the project begins.

A genuinely fixed price provides investors with much greater certainty than a quote that depends heavily on allowances.

What Is Included in RPG’s Turn-Key Price?

RPG’s fixed price also includes the turn-key finishes required to make the investment tenant-ready.

These can include:

  • Fencing
  • Landscaping
  • Window coverings
  • Clothes lines
  • Driveways and external finishes
  • Air-conditioning
  • Soft-close drawers
  • Stone benchtops

These inclusions help ensure the completed property is ready to compete in the rental or resale market.

A quote may appear cheaper simply because many of these essential items have been left out.

The Risk of Waiting for a Final Price

Builders using the standard Development Application process may not confirm a fixed price until planning is complete.

This can take between 6 and 12 months.

During that time, the cost of a duplex development could increase by approximately $100,000 to $150,000.

That increase may affect the investor’s finance approval, borrowing capacity and original investment calculations.

With RPG, the fixed price is locked early, helping remove this uncertainty.

Know Your Numbers From the Start

The best financial outcome does not always come from choosing the lowest headline figure.

It comes from transparency, certainty and knowing the complete numbers before committing to the project.

RPG’s fixed, all-inclusive pricing is designed to give duplex investors that level of control from the very beginning.

Speak with RPG to learn more about our fixed-price, turn-key duplex investment process.

Frequently asked questions

Where does RPG build in NSW?
Residential Property Group (RPG) builds throughout regional NSW, including Newcastle/Hunter, the South Coast, Goulburn, and surrounding areas. We generally focus on high-growth, investment-ready locations.
Because we’re focused on regional NSW only, we cover a large variety of towns. Please reach out if you have a specific preference.
A duplex investment can improve your cash flow by providing two rental incomes from a single property. With The RPG Duplex Investment Roadmap, you’ll enjoy a cash flow-positive investment from day one—minimising risks, maximising returns, and setting you up with a steady stream of passive income
Our turn-key approach means your duplex is tenant-ready faster, helping you generate income sooner and build long-term wealth.

Yes. New duplexes can generate over $20,000 per year in depreciation deductions — far more than older properties.

That improves your cash flow and reduces your taxable income, especially in the early years of ownership.

A quote is an early estimate. It’s usually based on limited information — often before a site inspection or proper planning assessment has been done.

That means it’s subject to change. In most cases, it’s just a rough ballpark to keep the conversation going.

A fixed price, on the other hand, is contract-ready. It reflects all known costs — including siteworks, approvals, materials, and finishes. It’s the figure you can take to your lender and build with confidence.

Owning a duplex or dual-key property can set you up for a more comfortable retirement by providing a steady stream of passive income.
With two rental incomes from a single investment, you can build a reliable nest egg that keeps your finances secure and maintains your quality of life.
Through The RPG Duplex Investment Roadmap, we optimise your build specifically for investment ROI.
The process starts with a thorough site assessment and feasibility study, and a fixed price is provided within just 10 days—compared to the industry standard of 6 months. This early clarity means you can secure finance from a position of strength, avoiding market fluctuations and hidden costs.
Our turn-key construction approach, with streamlined planning and fast-tracked approvals, ensures your duplex is tenant-ready sooner, thus maximising your rental income potential.

Every step is designed from day one to protect your investment, deliver consistent cash flow, and set you up for long-term financial success.

Because without it, you’re not in a position to move forward — no matter how ready you think you are.

Pre-approval isn’t just a formality. It tells you exactly what you can borrow, so you’re not wasting time on packages that won’t work. It also puts you in a stronger negotiating position when the right opportunity comes up — because you can act immediately.

And most importantly, it means your builder can give you real advice. Without it, all they can offer is ballpark figures and generic options — and that’s how delays and budget issues start.

If you don’t know your borrowing capacity, you’re not ready to build. It’s that simple.

Ask about approvals: are they using a Complying Development Certificate (CDC) or a full Development Application (DA)? 

CDC is typically faster and less risky. 

DA can take 6–12 months — and open the door for contract repricing.

 

Ask about their pricing: is it a fixed price, or does it include Prime Costs (PCs) and Provisional Sums (PS) that allow the builder to add extra charges later?

 

And ask about their financial standing: what’s their rating under the Home Building Compensation Fund (HBCF)? 

A builder with poor HBCF capacity could leave you stranded mid-project if they collapse — and that’s not uncommon in today’s market.

Look out for Prime Cost items (like cheap allowances for appliances) and Provisional Sums (for unknown siteworks or materials).

These costs often show up later — along with a builder’s margin. RPG contracts are genuinely fixed — no allowances, no surprises.

We provide a full defect period, structural warranty and referrals to trusted local property managers in your build area.

We don’t disappear at handover — we make sure your investment is set up to perform long-term.

Speak to an RPG Duplex Investing Expert