Buying a Campervan - need tips

It's the engine and chassis which will really count, otherwise you could be in for an expensive purchase, get someone who is mechanically minded to have a good look and hope there are some service reports etc to match. You'll probably find a lot older equipment inside but if it's been well cared for it should be ok. Check everything works before you purchase.

If it's a 5k van, how old is it, the mileage might be on it's limit.

I guess you could take a look at club’s Classified ads which may give an indication as to what is available in your price range.  Good Luck.

Try Autotrader online. A good bet may be a reasonable mileage ex-Japanese camper as the base vehicle will have come from a more benign climate.

But because their climate is more 'benign' Japanese imports don't tend to have the same anti corrosion protection as UK cars.

Be very careful as there are a lot of scammers in the used motorhome market.  Don't buy unless you have seen it and been able to give it a good examination.