I don't know if working in Spain is a good idea at the moment, due to recession.
I live and work in Portugal (that is in the same financial situation as spain at the moment) and it's horrible!
We usually charge lower rates than in the uk - 64 to 80 pounds ph! And I am talking about tall, slim, beautiful escorts doing incalls in nice flats! Street walkers charge as little as 15 pounds per bj.
But the state of the economy makes it really hard for us to even find work at those rates so everyone is lowering them. As low as 40 pounds ph with owo, a and cim. Like I said, this is the situation in Portugal and I believe its not very different from the situation in Spain.
I get by on doing a lot of outcalls to business men or guys that come on holidays. I get to charge 80pound ph outcall (and that is including taxi fare).
If you are really serious about moving why not do a tour in Spain and Algarve? Algarve is in the south of Portugal but a lot of german and english people there. You get to charge a bit more, and work a bit less.
And I forgot to mention...there very few agencies here. Very, very few! But there are some flats who have something like 6 girls working and one "madame". Men get there, chose the girl, pay and fuck. Its almost a 50-50split between you and the madame and its totally not worth it. If you are not working on the street, you wont have a problem with police, even if you share your incall flat with two other working girls.