I never find tools at the restore, or it's rare, but I recently scored a new stainless paper towel dispenser (which conveniently also holds a box of rubber gloves), for ~$7. I also scored 5 new stainless bins 6"w x 6"d x 14"l at $2 each. I've not found a use for them yet, but I'm sure I will. I also occasionally see some very good nuts/bolts/hardware and usually grab anything I may use in the future - at $1/lb for screws/nuts/bolts/washers/hardware, of any flavour, it's orders of magnitude less expensive than the local hardware store.
I picked up an old Dietz railroad inspection kerosene lantern not long ago even - $10, with original glass! It's in the middle of a restoration itself, which I may simply donate it back after I'm finished with it and let them resell it again.
On the whole, I'd say out of 5 trips there, it wasn't worth visiting on 4 of them, but it's still interesting to see what comes in and it's a helpful charity to contribute to.
The flare nut wrench is probably worth the $5 just by itself.