Yes they will and yes it is.
I had to pay 25% of the repairs to my van because of a late first service (my fault that as I had other issues going on in life)
I believe it was about £380 so full price would have been about £1500, it's the labour you paying for.
You can buy a Stanley damp metre from b and q for £40 and they are accurate, more so than really cheap ones but not as expensive as a protimetre. Or you can hire a damp metre from a tool hire shop.
I wouldn't buy at any price without a damp check.
One other thing that so many people miss, take some step ladders and have a good look at the roof, just in case of any damage that you can't see at ground level.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.