I agree with others. A new one is not going to be that much more (or at least what you should be able to get it for). If you are buying used to save money or perhaps have a lower budget, then you should really look beyond a couple years old and go at least 5 years or more. The savings will be significant, meaning you can get more for your money. The problem with buying a newer one (few years old) is that people owe not much less than what they paid for it. If they paid $70k 2 years ago, then they probably still owe between $65-68k today. Now of course, they could of put $10k down. But the private party book value is not going to be close to what they paid for it (and don't even bother to see what a dealer will give you for it). While they may have put $10k down, they aren't going to get that money back. At least not all of it. They more than likely will lose around half off it. The fact is that RV's lose value. Pretty quickly at the beginning and then around 10 years or so they start to start losing less at slower rate.
We have owned 2 pop ups, a TT and now a Class C. We bought all of them new with exception of one of the pop ups. And the one that we bought used, I got a really good deal on and ended up trading it in with our TT for our Class C. The dealer gave us twice what we bought the pop up for. Good used pop ups are hard to find and people are wanting crazy prices for their crappy ones. I watched the listings for about a month on craigslist and jumped on the one we bought as soon as I hit. Made an offer a little lower than what they were asking and they accepted. Worked out good. We had intentions of using the pop up, but before we could use it, we decided to trade up. I could of easily sold it on my own for about 2.5 of what we paid for it, especially if I would of waited for warmer weather.