How to use comparable sales to avoid overpaying

A price guide reflects the agent's estimate of what the property might sell for. In most states, agents are legally required to set a price guide that reasonably reflects the expected selling price. But the final sale price is determined by the market, and comparable sales give you an independent way to assess value.

Comparable sales tell you what the market actually paid for similar properties nearby. They are the closest thing you have to an objective measure of value. If you learn to read them well, you will walk into negotiations with a much clearer picture of what to bid.

What counts as comparable?

A good comparable sale (or "comp") shares most of these traits with the property you are looking at:

• Same suburb or immediately adjacent street
• Similar number of bedrooms and bathrooms
• Similar land size (within 20 percent)
• Similar property type (house, apartment, townhouse)
• Sold within the last six months
• Similar condition (renovated vs unrenovated)

No comp is perfect. There is always some difference. The goal is to find three to five sales that are close enough to establish a range. That range tells you what the market is willing to pay for properties like the one you are considering.

Where to find the data

Sold price data is publicly available in most states, but finding it can be frustrating. In NSW, you can search the NSW Valuer General records. In Victoria, you can access sales data through the Victorian Valuer General. In Queensland, the Department of Resources publishes sales data.

Property portals like Domain and REA also show some sold prices, though their coverage is not always complete. Paid services like CoreLogic and PropTrack provide more comprehensive data, including price estimates and historical sales.

On housematch, we show comparable sales directly on each listing. You can see what nearby properties sold for, when they sold, and how they compare in size and bedrooms.

How to read them

Start by looking at the median of your comps. If five similar properties in the area sold for $1.42M, $1.48M, $1.52M, $1.55M, and $1.61M, the median is $1.52M. That is your starting point for what the market considers fair.

Then look at what is different. Is the property you are looking at on a bigger block than most comps? That might justify a higher price. Is it on a busy road while the comps are on quiet streets? That might justify a lower price. Has the market moved since the comps sold? If it has been six months and the market has softened, the comps may overstate current value.

Pay attention to how long each comp was on the market. This is called Days on Market (DoM) on Domain and REA. A property that sold in two weeks likely had strong demand and may have gone above its true value, though it could also mean it was priced accurately and attracted the right buyer quickly. A property that sat for 90 days before selling probably sold closer to or below its fair value.

Be careful with auction results. A property that was "passed in" at auction (failed to meet the reserve) sometimes sells later by private treaty, and some data sources record only the final sale figure without flagging the auction outcome. A passed-in result tells you the market valued the property below what the vendor wanted, which is useful context. Check whether each comp went under the hammer or was negotiated afterwards.

Common mistakes

Using comps from too far away. A sale three suburbs over is not a comparable. Property values can vary dramatically street by street.

Using comps that are too old. A sale from 12 months ago reflects a different market. Stick to the last six months where possible.

Ignoring condition. A renovated house and an unrenovated house on the same street are not comparable, even if they have the same number of bedrooms. The renovation adds value. If you are comparing the two, adjust your expectations accordingly.

Only looking at asking prices. Price guides are estimates. Sold prices are evidence. Focus on what people actually paid, not what the agent asked for.

Using comps at auction

If you are bidding at auction, know your comps before you walk in. Set your maximum bid based on what the data tells you, not on the energy in the room. Auction environments can feel fast-paced. Your comparable sales data gives you a calm, evidence-based anchor for your bidding limit. They give you a rational anchor so you can bid with confidence and walk away when the price exceeds what the data supports. Our auction prep guide covers everything else you need to do before auction day. If the property is selling by private treaty, the offer guide walks you through how to structure your bid.

The data is available. It just takes effort to pull together. That is what housematch does automatically for every listing.