I found these two amps for $100 and I have heard they are good sq amps guy says there's something wrong with both of them he's not sure what but $100 for the two of them is it worth getting them fixed
not easy to fix and few people will even bother. I am one of those people but I already have some in need of repairs. luckily, most issues are power supply related and not mosfet damage. replacing the mosfets would be a chore not worth the effort.
some times people accidentally remove the jumpers not realizing they are required.
I like xtant amps and the 3300c and 603x are awesome amps. they are worth looking at. $100 is a fair price for them not working but all they are worth right now.