Car hire in spain on the whole has dramaticaly risen in the last 18 months due to the recession. It isn't the car rental companies fault to be fair, their hands have been forced.
Whats happened is that all these companies mostly have buy back contracts with the manufacturers, so when they have returned their fleet the banks have then gone back on their promise to fund new stock. So their fleet have been decreased hugely. Here on the mainland there was a huge drought last Summer, when you could find a car they were extortionate. Obviously their over heads havent decreased so they ALL had to increase their prices.