Not that poor ($160) : Take the incredible, like seriously ****ing increcible! Xin SuperMacro III on the FS forums and laugh at everyone who paid more than double what rhythmdevils is asking.
I listed to his amp at the Fairfax meet and am smacking myself upside the head every time I see it still on the FS forums, it's better than anything out there at the price-range or within the ~ $200 range, oh did I mention it kicked the Pico's pico-sized ass?!
Semi poor ($100) : Mini3, a few on the forums by DIYers and a few better quality builders making them at $125 new. The main thing that usually separates average builders from professionals is using thin film resistors (about $1 each) vs thick film resistors (10 cents each) and higher quality C0G/NP0 vs XR7 caps. Personal preference, I build my stuff with thick film and C0G/NP0 caps because I didn't notice much difference in the resistors - you're looking at the last 5%.
Very poor ($50): GoVibe 5 or thereabout, I seriously loved this amp for the niche it filled, it's a fine quality amp at the $50 range and it seriously kicks butt for that price! It's fantastic to build and sell an amp on such a budget - it's possible, but profit margin is TINY (if existent at all, but it must be), so I think it's for the love of the art and I love to see that as a DIYer.