How to Estimate Risk in Reselling

Risk = downside × chance; in resale both are estimable

The formula is only useful because both parts come from data you can get. The downside is arithmetic once you know the price where similar items leave the market fastest. The chance is your own history: of the last ten similar buys, how many needed a markdown, how many never sold, how many arrived worse than the photos. Where your history is thin, round the chance up, not down — the cost of caution is a skipped buy; the cost of optimism is stock.

Downside 2: it sells too slowly (cash days at risk)

A second downside hides in the calendar: even a full-price sale after 90 days is a worse outcome than a markdown after 20, if the cash had somewhere better to go. Cash days at risk = buy price × days until the payout. Say 80 zł sits for 60 days in a category whose median is 20 days — that is three turns of a fast category missed while one slow piece decides.

Decision rule: if the expected cycle is roughly twice your category median, demand a bigger margin than your floor or walk away. The chance side — how fast comparables actually leave the market — is what checking resale demand measures before you buy.

Downside 3: condition or authenticity surprise

This downside is lumpy: nothing happens, or the item returns a fraction of what you paid. Pre-buy, put a price on each surprise:

• Cleaning and repair: if the photos hide wear, assume you pay for it. Add a number — 10 zł, 20 zł — to the cost side before comparing prices.
• Fakes: if you cannot verify authenticity, price it as a total loss in the maths. A counterfeit that gets flagged usually returns nothing, and the flag can come weeks after the sale.
• Wrong expectation: undisclosed damage found later turns a profit into a refund plus a dead listing.

The rule that follows: never buy an item whose single worst realistic case is bigger than your best realistic profit, unless you can actually verify the thing that would cause it. A 100 zł worst case against a 30 zł best case needs certainty you usually do not have.

Downside 4: platform rules, returns and payment trouble

Platform trouble is the downside people forget to price, and it has two parts. First, the money waits: on Vinted's UK help pages, checked 13 September 2026, payment shows as a pending balance until the order completes — the buyer has 2 days after delivery to confirm or report a problem — and on OLX the payout is ordered when the buyer confirms, or 48 hours after pickup or delivery if no claim was filed. Add those days to every cycle in the sections above.

Second, the sale can reverse. Vinted's UK, Polish, French and German help pages cancel the order automatically if it is not shipped within 5 business days. OLX's Terms, in force since 27 April 2026, refund the buyer automatically if you do not confirm the sale within 72 hours of the order, or do not hand the parcel to the carrier within 3 working days of accepting. Either way the cash goes back to the buyer and the item is back on the rail — a full cycle restart with the clock at zero.

A pre-buy risk checklist you can run in two minutes

Run it before every non-trivial buy; each line takes about twenty seconds:

The discipline is in the order: price the downside first, the chance second, and only then look at the profit. Done that way round, resale profit stops being a surprise at the end of the month and becomes a decision at the till.

Related guides

• reseller cash flow
• how much inventory to keep
• the pre-purchase authentication checklist