If I rent an apartment from a private person would I need to use a gestoria ?

short answer no. But it helps if you speak spanish.

We rented ours through an angency only becuase we didn't (and still don't) speak a word of Spanish. The main point of your contract is how much the landlord can raise the rent each year, I've heard 5%, doesn't sound like much untill you realize that 950 (which I currently pay) will rise to 1500 in five years, that's serious cash.

Most people I talk to say there landlords try and get an increase above that.