I don't know much about Marbella, but we did borrow a house for two weeks, south of Alicante, a year after the Financial Crisis. c.2010? It was clear that the price of apartments and houses were almost zero. Very sad for the residents. Even more so after Brexit.
Re. 50K watches, Well, you have to ask 'Why'? If it make you feel that you have a bigger penis, then, go for it!
Otherwise, engage brain and stop being manipulated.