$1000 USD a month is nearly $4000 pesos a month rght now. That seems a lot for an entry-level position. I would think you are probably looking at closer to $2000-$2500 pesos, particularly for the PHP skillset, for entry level positions. You might be able to find something for $4000 pesos nowadays with the inflation the way it is (I highly doubt it), but the higher the pay the more people will be looking for those jobs.
I hire .Net programmers, but I have a buddy who sometimes hires PHP/MySQL guys to modify his vBulletin forums and he pays between $15 and $20 pesos an hour. 20 pesos an hour would be about $3500 pesos a month. These are not entry-level guys that he uses.
If you are looking to join a company that provides services to local companies, you will be paid less than a company that tries to provide outsourcing for companies from North America, Europe or Australia. Most outsourcing companies here will tend to concentrate on .Net because most business (at least in the States) tend to prefer .Net for business applications. That's not a hard and fast rule, but it complicates your position.
The IT market here is pretty active and it will be difficult for a foreigner to find a job with a company when there are many, many well-trained people already working locally in the market. If you speak Spanish, you may have a leg up on some fo your competition here in that you also speak (natively) English, which would be great for those outsourcing jobs. I would say that maybe 25-30% of the programmers here speak pretty good English. If you don't speak Spanish, you will probably not find a job at a local company,
Your best bet may be to find contract work from the States and work it long distance. Something from Guru.com or RentACoder.com, etc maybe?
