eBay. Just wait for good listings. It's true that there is a non-negligible chance of getting burned, based on the general used laptop purchasing experience - but I've bought several and they've all worked as expected, pretty much.
This isn't due to any good qualities of the sellers. It's because ThinkPad makes damn good, sturdy laptops that are quite idiot-proof. I mean if you sit on your balcony and drop your laptop off the edge - that might destroy it. But it's going to take something on that level, and most people aren't that careless with electronics.
So you can be reasonably confident that anything ThinkPad you buy, if it isn't visibly damaged in the picture, will work as expected, in my (anecdotal) experience.
This isn't due to any good qualities of the sellers. It's because ThinkPad makes damn good, sturdy laptops that are quite idiot-proof. I mean if you sit on your balcony and drop your laptop off the edge - that might destroy it. But it's going to take something on that level, and most people aren't that careless with electronics.
So you can be reasonably confident that anything ThinkPad you buy, if it isn't visibly damaged in the picture, will work as expected, in my (anecdotal) experience.