Well a couple of years ago, when the dollar was $1.99 to the £, a Robinson would have been a great investment, not to mention a lot of fun. I'm not sure could say that about Spanish villas; I suspect it'll be a loooooong time after you've retired that you'll see your Marbella purchase price reflected in a valuation
Good luck to you; I hope you enjoy looking at your chum's Gazzer when it arrives