how long do campers last

"How long is a piece of string?"

It all depends on if it was perfectly dry when packed away, where is it stored, how it is stored, is it in a humid environment, etc?
As you say it is out of the elements, may be a good idea to open it up a couple of time s ayear to air & make sure that ants haven't decided to nest in it, as they did in one of my tents.

The majority part of the camper will survive indefinitely, but a couple of things that may happen if it is kept out in the sun.

1. The paint will fade over time and become dull.
2. The waterproof cover may be adversely effected by ultraviolet rays from the sun and become brittle over time, thus loosing the waterproof capability.


Bill.

Oz doc,
That's a bugger,
If you are to hold on to it, I would get a good quality Silver tarp bigger enough to come right down and partly underneath the sides and rope it up nice and tight. To stop ants and other crawlies, use a surface spray once a month around and underneath. Is it going to be parked on the grass? because this will cause rust on the bottom side of the chassis and underneath, if it is, it may pay to spray the underside with Black Jak or something similar(under body sealer), storing it on a concrete slab would be better if you can. Moisture is going to be your biggest concern, pack it up completely dry and keep it dry.
Hope this helps. Hope you get back into it sooner rather then later.

We were in a similar situation to you, and in addition we were building a house so really needed the money as well, coupled with having changed the main vehicle to one that wasn't suitable for towing a 4x4 camper.So we ended up selling ours. But now that a couple of years later we do have a fourby again and we are looking to buy some sort of camper again.

In some ways it would be good if we still had the original camper trailer, mainly because we lost a hell of a lot of money selling it but also because it did suit us really well. In other ways it's good, we can get something even more suitable for now and for down the track too (when the kids eventually leave home etc)....well we're in a toss up of saving up for a you beaut expensive one, or staying with our touring tents and getting a cheaper sub $10k offroad trailer built just to cart all our gear etc.

Like you I hated seeing something we paid $20k for sitting there and doing nothing. It's a big decision weather to sell or not, I guess you would have to consider how ideal that trailer is for you now and into the future, if there is nothing else you'd rather buy (or think you could afford to buy) then I'd hang onto it.