I’m no expert on Valencia city centre but from what I have seen there are some real bargains to be had at the moment. Graham Hunt of Valencian Properties seems to know what he is talking about. Perhaps have a word with him. I would say in general that the feeling is that property prices are going to go up rather than down which helps to reinforce asking prices but there is still a fair amount of subjectivity involved in pricing in Spain and again, of course, it depends on the vendor’s circumstances. You’re not going to insult anyone with a low offer to the extent that they will not talk to you again.
Hope that helps