I'm trying to sell my flat later this year once my tenants move out (been an accidental landlord for two years, desperate to offload the place as soon as contract runs out)
I think from a couple of sales which fell through 18 months ago that the flat has rising damp. It was treated for it 20 years ago. Should be under a 30 year warranty but we never got the correct paperwork to do this when we bought it 
Anyway damp came up on previous surveys, and was one of the reasons the buyers yes multiple buyers pulled out hence accidental landlord gave for pulling out.
I'm happy to drop the price by whatever the damp treatment price is. I guess this might be in the range of 2k, no problem!
Flat is in SE London and likely to be in the 450k region.
Would this put you off? Or would you ask seller for a discount, and happily proceed if they were happy to knock the treatment cost off the price?