not to oppose you cherns, but i think you have to enjoy the tone you're getting. i get really pissed when no matter how hard i try, i cant get an 'OK' tone coming out from my amp. i mean, you need motivation to play.
definitely you don't need the best amp and cab out there but something reasonable.
get smth between 30-50W, so that when your guitar buddies bring their 15W amps over for fun, you won't be drowned out. and you can recreate those deep lows and play around with the settings you have and see what interesting tones you can come up with.
makes more sense if you look at it this way, rather than just a 'finger training' amp.