We sold our 5ver through them...generally good to work with. We had them list the price at a few $$ higher than they wanted, but in the end it worked out OK just took a couple weeks longer to sell.
Efficient and well run operation. They don't take too much of a bite from the seller/consignee.
I'd be leery of a 16 year old unit if it has been sitting in the Texas sun that entire time. Shoot, I'd be leery of a 16 year old unit in any case, but (particularly with the good reputation Alpenlite's have) I'd mostly be concerned about the shape of the roof, penetrations, sealant, etc.