I do on a regular basis. I’m awaiting two deliveries of used books from Amazon Marketplace as we speak… er, write.
Just got my delivery!
I ordered Reversible Errors by Scott Turow. Hardcover. $3.99 - hell, shipping was about the same price, so I got a hardcover novel for about 7 bucks.
And since the retailer was in the same city, I got delivery in basically 2-3 mail delivery days. And it’s in frickin’ EXCELLENT condition.
I would hesitate, however, to buy from someone with little to no history…
I have found that, in general, the prices are 50-100% higher on Amazon than from a local used book shop. Of course finding something specific in a used book shop can be an adventure. But you can access the actual quality prior to the purchase and don’t have to wait for shipping.
My strategy is to look in the few shops around here and then look on line.