This is an impossible question to tackle, only because there are so many intangibles. The FIRST and most important point is that you're purchasing a house on wheels, rather than a vehicle you can live in. Floor plan first, then chassis.
Many would advise to purchase used over new, especially if you're new to rving. You just get to skip past losing the big depreciation hit of a new one. Used MAY already have the "kinks" worked out. Of course, you can't be sure it was cared-for properly. If they will reveal maintenance records, you may gain some confidence, but it's still a crap shoot.
That said, remember that even new coaches will develop a punch-list that needs to be completed before the coach is right....doesn't matter how much it costs. Even a $2MM coach that is lovingly custom hand-crafted will have items that need adjustment. Less expensive coaches are manufactured....understand that....quality control also costs money.
Figure out what your willing to spend and then look at what falls into your price point...new or used. Lower price point usually means lower quality....period. Soft woods are less expensive than hardwoods.....same for flooring, cabinetry casework, countertops, appliances, house construction methods and materials......better costs more.....so does fit and finish....just like a house. Character of the exterior skin also is in play.....like vinyl siding versus brick.....fiberglass with vinyl stickers or full-body paint with buffed clearcoat.
Chassis are also kinda like that....stronger costs more.....same for driveability, ride, powerplant, and towing......
No matter, it will need to be fixed......sooner or later....they're man-made.
I've owned 4 motorhomes in 5 years...in order: a 31' Damon Chateau C, a 40' Damon Essence (souped-up Tuscany), a 40' Phaeton, and tomorrow, I'm driving a new 43' Entegra Aspire off the lot. At this point, I think I've bought the best coach I can afford AND my LAST COACH.....but then I said that before.......whistling.
Do your homework.
All the best in your quest.
Pat & Medarda Bauer; Tess and Tighe (our fur kids)
2013 Entegra Aspire/FL/Allison/Edge
Entegra Coach Owners Association
Sun City Center, FL