If the sale is local, and you can be assured that it works before buying it and that it looks in good shape, and of course the price is reasonable, then it isn't that risky. As long as you then don't try to drive multiple sets of speakers to deafening levels, you will likely be able to use it for a long time to come. Just don't abuse it, keep it clean, use it regularly, and it will very likely work a long time. Always possible it won't, but it likely will. These things were well built. Bought a SX-980 used that still works perfectly, and I bought a used SX-1980 that I use every day, sometimes for many hours a day, and it has been flawless.