I spotted some in Supermercado Janet today, about 200 peso iirc.
Next to where the verizon (ahem, codetel, claro) desk is, in the same isle as the dog food. They also have all the sprays. Anything with deet stops the skeets.
I recommend screens! If you own you're house or condo make the investment - you won't be disappointed. The only time we have bugs in the house is when someone leaves the door or window open for any length of time.
Thanks to everyone for all the useful info.
Yes, there are screens on the windows, but some of the screens have holes. It's not like there are heaps of mozzies buzzing around, just enough to give me a new bite each night. I can't be 100% sure that is what is biting me.....but....one night I did hear one of the little buggers buzzing around despite the fan being on.
If your screens are like the ones we have, and like the ones I've seen elsewhere are, they are easy to repair. The screen is fabric mesh held in place by thin tubular rubber pressed into a channel. You can buy the fabric used in the screen at most hardware stores.