3000 pesos, around US$225
Not much in the way of interesting/quality bikes make it down this way. And ANY decent frame is worth a little bit more here, for that very reason.
Each market is unique, and you would know better than I what constitutes a reasonable price for a decent bike in your own market.
The question then is whether this is a "decent bike" or not.
I will offer you my thoughts for your consideration:
1) I can't tell what's under the green paint - it could be a very decent frame, but you should note that the front fork and handlebar stem are replacements, for what could have been crashed. Collateral damage could be concealed by (what I guess is) an amateur can paint job. It would be best to inspect it for this in person - plus, the weight of the bike, and the details will let you know if it is a high quality frame or not.
2) Fancy lugs like those were generally used on mid-upper level bikes in the 70's. but generally, people don't build up especially valuable frames with green cranks. You have to appreciate that it is going to cost you a lot of money and time to put this bike in order an to replace the missing components - starting with the BRAKES!
3) Mixte style frames are in vogue and tend to cost more than regular frames: Of course, it still has to fit you if it is to be worth anything as a rider, and they tend to run small.
4) If you really like it, and have the money to spend, it does not matter if it is technically "worth" $225. What matters is the pleasure you will derive from fixing it, owning it, and riding it. - It is a cool looking mixte frame, that's for sure!