I don’t know for sure, but I think that those who for some reason stopped mining sell their equipment. Look for ad sites. But I probably would not risk buying used equipment. In general, I am skeptical about such things. It is easier to take a new powerful machine for mining, according to its financial capabilities and characteristics. Which one do you think suits you the best. Mineri provides an opportunity to purchase productive equipment at a good price. In addition, they have all the necessary range of bitcoin mining hosting
https://minery.io/ . The company is reliable. Helps newcomers to develop.