Actually making money reselling
The calculator tells you the number. These are the habits that make the number good in the first place.
Price to sell, not to prove a point
An item sitting unsold for three months isn't "holding its value" — it's tying up cash you could've reinvested. Sold at a modest profit beats unsold at a big one.
Cost everything before you buy, not after
Run the numbers before you commit money at a thrift store or wholesale lot, not after. It's easy to justify a purchase in the moment and do the maths later — do it the other way round.
Match the platform to the item
Fee structures genuinely change what's worth selling where. Vinted's zero seller fee suits lower-value clothing; eBay's reach suits higher-value or harder-to-find items where the fee is worth it.
Shipping is a cost, not an afterthought
Weigh and measure before you list, not after someone's bought it. A miscalculated shipping cost is one of the most common ways a "profitable" sale quietly becomes a loss.
Track margin, not just profit
£10 profit on a £15 item is a very different business than £10 profit on a £150 item. Margin tells you how efficient your money is, not just how much you made on one sale.