Join Date: Sep 2007
Bikes: Litespeed, O'Brien, Specialized, Fuji
My feeling is that you need to do a very careful inspection just like with any other used bike. You can't easily have the frame inspected for alignment, so you have to visually check everything. Is everything straight and true? Any scuff marks anywhere, dents, scratches, scrapes? How does it ride? That said, I would check around all welds very carefully for cracks, especially the bottom bracket, and look for any evidence of a frontal hit, such as wrinkled top/down tubes or fork damage. The bike should be clean so you can see, and use good lighting.
As to repairability, it probably depends on whether anyone in your area can do ti repairs. Even something seemingly simple might be difficult if no one around knows how to do it and has the equipment. Otherwise, I have no idea how hard it is to repair ti problems.