Mike, I´ve spoken to an English Estate Agent in Spain who has told me that it would be perfectly reasonable now to offer 35% less sometimes even more on lots of properties. He appears to be telling it like it is.
I think if someone wants to buy in Spain (probably not wise at present) then make loads of silly offers in the hope you strike lucky. Then another offer on top of your first to compensate for the dreadful exchange rate. 😉