How do I know if a picker is making me a fair offer?

Start by doing a little homework. Look up completed sales of similar items, not asking prices, to get a rough idea of what they actually sell for. Keep in mind that a picker has to cover costs and earn a profit, so an offer well below retail is normal. Many pickers aim to buy at a fraction of resale value, though the exact margin varies with the item and how quickly it sells.

Getting more than one offer is the simplest way to judge fairness. If two or three buyers offer similar amounts, you are probably in the right range.

Be cautious if someone pressures you to decide immediately, offers a lump sum for everything without looking closely, or seems very eager to buy one particular piece. Those can be signs that something is worth more than you think.