Sporting goods at thrift stores are pretty risky. I've never seen a piece of equipment that wasn't beaten into the ground or cheap to begin with. I'd say don't even bother with skis, they depreciate extremely fast, and the chance of finding skis nice enough that they would retain any of their value is pretty much zero. Nice skis get bought by people who would never donate them to thrift stores, and even if you found a pair of mid-level skis from two years ago they still wouldn't be worth selling online. Skis are kind of like cars, unless they are brand new and the current model year, depreciation is lightning fast. Unmounted, New skis from 2012 probably sell for less than 1/4 of what they went for brand new, I could probably get a pair for $100 from a ski shop, especially now that it's spring. So yea, don't mess with skis. Same with ski boots, too much risk, and they are super heavy. Skates are hard too, you pretty much never see ones worth anything at thrift stores. Jerseys can be great, but there are 25 worthless ones for every remotely valuable one. Look for ones with sewn lettering, not screen printed. New looking soccer, football, and baseball cleats can be good if they're Nike or Under Armour and in good (nearly perfect) condition.
Hope that was helpful, I rambled for a sec there.
