Insight re: purchase

The roof definitely looks dirty and moldy. But just dirt is not a real detractor. It's all the sealants around the penetrations that you need to look at. From what I can see there is no current cracking in the pictures so it is very possible that the owner was being honest about the roof being regularly inspected and repaired as needed. Of course the hardest thing to see is the roof sides where the roofing go behind some trim pieces. 

An update to my original post: We did go and took a look a few weeks ago when this opportunity had dropped in my lap. I had also managed to track down an inspector willing to take a look (after 4 ppl!!) if we decided to proceed, but ultimately, we opted not to move forward with this rig given our concerns re: the age/roof etc..and also after accepting a realistic view of how often we could actually use it in the immediate future. With that said - I am curious for thoughts from those here with more familiarity about these rigs. We showed pics to friends with some RV history, and they cringed when seeing this roof (lots of tree canopy/shade, has been campground kept since 2011, told roof has been religiously sealed/checked 2x each year, body gets washed, etc).  I know an inspection would've determined more about the condition of the roof if we went through with it - but I remain curious of the expectation of whether this is what a 14 yr old RV roof would "normally" look like based on age & location, or perhaps this is just best used as the perfect Wet & Forget "before" photo....?? 

 

There's really a ton to look at to see if the 5th wheel's in good shape or not... But I think one of the most important things I'd look at is the roof. Look for signs of leaks, cracked or loose sealant, worn out caulking around vents, skylights, or the AC unit... These are prime locations where water can get in and even if you're new to RV/trailer camping, I'm sure you can understand how bad water damage can be. The good news is that you can also patch up RV roof leaks if they do happen... so even if the rig's roof you're looking isn't in the best shape, you might just be able to get the owner to knock the price down a bit. 

Could be very reliable if it was well kept, you can get a feel for that if the owner is forthright about what they’ve fixed and maintained. 
14 years outside, the roof could be trashed, or 14 years stored under cover and out a couple months in the summers is a different scenario. 
As you know there’s kinda 2 separate components, in general. The house and the chassis. 
In this case the house is presumably well used. (A dozen years as a “summer cabin”). Could be super easy use if it was a couple old people who spent a month a year there or could be worn the f out if it was a family with 4 kids and mooching cousins who spent all summer every summer in it. 
The chassis should be like new save for a little maintenance but that’s of little value to you if you’re just parking it too. 
Personally I’d be targeting one miles on it and light use on the house rather than the other way around. 
But it’s impossible from your description to tell if this trailer is actually a good value. 

look up mobile rv techs in your area, when buying a older rv it is well worth the couple hours of labour you might have to pay him to go look at it with you.  he will know where to look to find the issues and not be blinded by excitement like a purchaser will be.  he can also give you an estimate of what it would cost to fix the issues or if they are even worth fixing, and if you should buy it or run away. 

Make and model would help to estimate value and such.

Condition is key with older Rv's. No one on here can offer an armchair diagnosis of an old RV and all it's systems and structure especially with no details about make model or condition. Best advice - get a qualified RV inspector and have a thorough and documented inspection before you make any offer. Then you'll know what you're dealing with.