New or Used? Very personal decision.
I bought used, 6 yr old trailer, 6 yr old truck, purchased separately. Both VGC, about $21K total. I have pretty much bought used all my life. I am reasonably handy, and understand that whether new or used, I am going to have to put hands on and $ in. Now, I don't full time, don't make long trips. I do some things myself, some things I hire. Pick and chose.
From what little I have seen of buying new, there will be defects (more or less serious) in a new trailer. Dealer corrects these of course, but you gotta take it to them. It can take several visits. A used unit has presumably been thru this. New has a warranty, used does not. New is only new while its on the lot, after that its used. Used stuff fails, new stuff fails.
As for parts, I don't think you can count on much of anything being available from the OEM for very long. They change designs too much, they don't seem to stock parts for previous production. Then you are looking at aftermarket or salvage.
There is just tons of good used stuff out there. I would also say that, for your first camper, no offense, you won't know what your are doing with it, I didn't. Find a good used one, you won't feel quite so bad when you ding it. Learn how to run it, and if you really like what you are doing, and the type of camper works for you, then go new.
That's my take:)