Looking for a house...

Before I got here in Monterrey I knew I wouldn't stay at my grandpas house for long, I wanted to move once I got a job, but that isn't possible, there are things that I need to do first, either save some money to buy some things that I really need, like a refrigerator or a bed (since I sleep at a couch), and some other things, but I really feel that those two are the really essential, and a water boiler, although, most houses have them already.

For a few weeks now, I have been looking on the internet for house prices and the location, I wan't something either downtown or close to the metro, preferably I want something that is near a park too, or somewhere I can exercise. Now, the prices I have seen go from 1000 pesos to... well they go to high, but I am only considering houses at 3000 max, I have seen some near where I want it, but since I still don't have a contract at my job, only the two month contract that I got when I started, I don't want to take the risk, not yet, and because I still need to save some money.

Now, how much should I really be paying for what I earn weakly? If I find a house at 2500, which are the ones I have liked the most, some even have furniture and other things, I'll end up using like 55% of my salary in rent, groceries, services and transport, therefore having the 45% of it free for me to do whatever I want, I think that is a good deal, so I might get a house at that price, I just hope that I can get one where I want it, and that I get my contract at my job, lol.