I've also been waying up the differences lately too. I'd love bricks n morta as they mostly hold their value, the taxes are cheap, and although my budget is similar to yours you can still find some nice properties.
I've been looking on "caravans in the sun" which have many different sites across Spain. Plenty of cheap vans for every kind of budget BUT then factor in the rents and your looking at 2.5k to 4k a year which although plenty of amenities it's still money down the drain.
The biggest problem I'm hitting is becoming a resident and all the new rules and finances they now want. Hopefully by the time I get to buy they'd have realised how stupid they're being out pricing people who want to retire over in Spain