Is that sale price real?

A kilo of coffee marked down from $46 to $32 feels like a win. But if it sells for $32 most weeks, then $32 is the real price, and the $46 is only there to make it look like a deal.

"Every few weeks they can have it half price and everyone buys it thinking they are getting a bargain."

That's one shopper on Reddit, and our numbers back them up.

Supermarket coffee is on special most weeks

Our supermarket price tracker records the price of every 1kg coffee bag at Coles, Woolworths and Aldi each week. Over seven weeks, from 26 August to 7 October, 42 of the 81 kilo bags went on special at least once. 13 were on special in half those weeks or more.

Grinders Espresso 1kg shows how it works. The shelf price is $46, but Coles and Woolworths take turns putting it on special. In all seven weeks, one of them had it for $32 or $36.50.

Some roaster sales work the same way

We check roaster websites every week too. We looked at 60 roaster coffees that show a sale price now and that we've tracked for more than three months. Only 12 of them were listed at their "was" price at any point in that time. We check weekly, so a short spell at full price could slip past us, but most of those "was" prices weren't charged while we were watching.

Compare the price per kilo

The surest test is what a kilo costs, whatever the label says. Right now, the middle price for a kilo of supermarket coffee is about $43, across the 80 kilo bags we track. For an Australian specialty roaster it's about $65. That's the market price our Bean-o-Metre uses to rate each roaster as Great Value, Market Rate or Premium.

So a roaster's kilo on sale for $50 is a good price. The same $50 at the supermarket is more than usual.

How to tell a real sale

• Check the price on a few different weeks. If the sale price keeps coming back, that's the real price.
• Compare the price per kilo against those two numbers.
• Add postage before you compare.
• Treat 10% off as normal. 53 of the 95 percentage-off codes on roaster sites right now are 10%, and only 7 are 30% or more.

We do the checking for you

Every week we go through roaster websites and their newsletters for the latest deals. Each Friday, our newsletter shares the ones worth your money.