There's a few - to me - truths obvious about this notion posted.
First off, IMO, EVERY piece of equipment, basically no matter how bad as long as it is playable, has at least one good use, at least one good sound for which it is perfect.
All you need to do is find it and lock onto it, and it can be the best sound ever for some purpose and totally enjoyable. I don't care if it's the rattiest Danelectro and cheapest plastic belt-clip amp, it could have an insanely good dirty blues wrunk ever for some situation.
Secondly - who's saying a cheaper amp can't be good? It depends entirely on where and how you play it, for what purpose?
A cheaper amp isn't built for big stages and massive volumes etc. but there is no innate reason it should be any worse than another pile of electronics for the volumes and uses it was designed for. It's not like great big amps are made of some precious metals cheaper amps don't have, they're just built for years of use, loads of volume and hard touring...a small cheap amp will actually likely sound BETTER than a big super-$$ amp in home setting.
The same goes for pickups. There are NO greatly significant differences between any reasonable quality pickups. Sure, an expensive one might be less microphonic or brighter thanks to better materials, but again, it depends much more on the amp and the situation whether those qualities matter or not. A cheap pickup may be just the ticket for not too bright a sound from a smaller amp and sound HUGE and warm. An electric pickup has very few variables and each has just a tiny effect on tone, aside from the actual construction (single/bucker etc.) but just as with amps...any may be great.
So don't ever think cheap equipment is bad sounding or inferior for the use they're made for - that is simply NOT the case.
Think of the countless superb recordings which have been made with tiny amps in studios, often really cr*p hardware, and still made sound great.
In fact, if someone hadn't had to play with a busted cr*p amp that buzzed like crazy, we'd never even discovered overdriven sounds, I do believe...
Dee
"When life's a biatch, be a horny dog"
Amps: Marshall JVM 410H w/ Plexi Cap mod, Choke Mod & Negative Feedback Removal mod, 4x12", Behringer GMX110, Amplitube 3/StealthPedal
Half a dozen custom built/bastardized guitars all with EMG's, mostly 85's, Ibanez Artwood acoustic & Yamaha SGR bass, Epiphone Prophecy SG, Vox Wah, Pitchblack tuner plus assorted pedals, rack gear etc. for home studio use.