We've done it twice - trade-in figures were ridiculous. Both times we sold our trade-in to two different sons so that at least they'd reap the benefits instead of the dealer. First time our trailer was only a year old, second time 2 1/2 years old. But, as others have said, we are pleased with our decision, and it was well worth it in the end. If we'd kept what we had, it would have just kept eating at us that we wanted something different.
2017 Melbourne 24k - 2003 Jeep Wrangler
2013 Premier 19FBPR; 2013 Rpod 177 HRE
2011 Aliner Sport; 2008 Little Guy 5-Wide
1980 Shasta 21; 1981 Coleman Tent Trailer
1978 VW Westfalia; lots of tents