Tried it only once. Bought a $2,000 LOMC used for $800. Advertised as < 50 hours, but it arrived with a seriously off-center cantilever. It seemed to me then and now that it would have taken much longer than 50 hours to do that.
Others have been luckier, obviously. In the end, you assess the risk vs. the reward (savings) and make your own choice.