I put my spare NAD 7020 receiver that I keep around into service in my second system a year or so back when my other pre-amp there died, and I have been hard pressed to find a good reason to take it out again. IT does quite well in there!
I bought it for $25 used in a pawn shop in Alabama back around 1986 or so.
One of these days, I'll swap it into my main rig in palce of the ARC sp16, just for kicks to see how it might stack up.
It's not a good idea to use cost as the main metric for what to use or not use. Better to have a budget that need not be extensive, be well informed, do not overpay, maybe but used to try, choose a weapon wisely, and then use your ears to judge how many $$s are needed to get good sound that you like.
In regards to resolution/detail, the easiest way to find out what is possible is with computer or good quality portable devices and a good pair of buds or phones. It's the low cost way to hear what you might hear in a digital recording without bringing expensive home gear, room acoustics, etc. into the equation.
Digital audio has come a long way...do not discount it totally until heard done well, which is not all that difficult these days.