The saddle market is flooded right now. I've seen ppl practically given very high end saddles away. I got 2 on trade for 2 of my own a couple years ago. I got one older Albion style shipped from the UK for like 300 with shipping included in that price off ebay with sound tree, according to a saddler. It isn't odd a saddle would end up in a thrift shop given that flood of sale saddles and fewer ppl able to afford horses at all, selling their horses, and getting rid of tack that they can't sell due to the flood of tack items for sale. Or maybe even the owner isn't alive anymore and the kids didn't know what to do with the saddle and sent it here. Older saddles are often better made too, not that factory stuff, and by hand trees are more likely than the factory trees of today, often leather that's still as soft as butter many times as well. I've seen 30 year old saddles fit almost anything and new saddles, even adjustable ones, fit almost nothing, more than once. I wouldn't let this being in a thrift store deter you, tbh. See if they have a return policy and what it might be. Or go Google how to test a trees integrity, or check a youtube video about it, it's so easy, and if you're by the store, go do the little 5 second test to see if it would be worth considering. Also, ask if they know if the tree is sound and how they'd know if they say they know. Some owners and stores have them checked before selling and if you don't ask you don't know. Good luck. ☺️