When we looked at a 2000 (35') and 2001 (32') Allegro Bus it seemed to us that the 2001 was built a lot nicer as far as cabinetry, etc.
52k isn't unreasonable as an asking price (unlike those folks out there asking 80 or 90!). My personal opinion is that you can counter that, but I don't think you're going to pay in the 30's, for example. So what is really important.... most important... is condition. You can burn through $4,000 that you "saved" really quickly if they have the original tires, aging awnings, etc.