Amp's that are better sounding than a nad 3020

I doubt you are going to find anything that sounds better than the NAD for 300.00. Save your pennies, then move up...

I think the more significant question would revolve around the age and condition of the parts in ANY 40-50 year old audio amp. If any integrated amps (including the NAD) have been serviced by a reputable repair shop then one can do a comparison. If I were looking at what I could buy for $300 and many older amps were found, I must include another $300 for service and parts at a minimum. If I didn’t take into consideration parts condition, parts availability, quality service.... that would be foolish. I think an amp for $300 is really an amp for $600-$800, or you will have failure problems very soon for buying an old integrated amp for $300.

Check out Cheapaudioman on You Tube. He focuses on lower priced but still great sounding equipment, and has reviewed a number of amps in your price range. 

Wait until you can afford a decent amplifier.  Never heard an amp could cost only $300.  

I must be rich..one of my amps cost more that 3k...and that's considered budget in some minds...all relative I guess. Not much out there for 300 bucks, except a used something or other, and being old, potentially a headache.