One thing I have learned about quality of almost anything, there is no such a thing as free lunch, which means that most of the time, you do get what you paid for....but sometimes, you can also get a LOT more than you bargained for especially when it comes to equipment. For most of my experience, electronics have been mostly reliable...but then there are the stinkers, for which I paid good money for but the reliability has been questionable. The issue with affordable amps, they sort of fall under the radar of what we call expensive, especially those Ebay tubed amps made in the far east, but then, when they do fail, there is not much incentive to get them fixed especially if the manufacturers are overseas....the shipping is prohibitive. The dilemma falls whether it would be worthwhile to get the piece fixed domestically because of the price paid.
I feel I rather purchase a used quality product and if the necessity arises, I get it fixed here rather than gamble my money away trying to get away paying $$$$ just to get burned with unexpected repair costs.
Of course, this is just myself talking here.