If you want to live in a more rural area then The Dr is very inexpensive compared to The US, plus cockfighting is legal (as I'm sure you already know). Places like Cotui (where I'm from originally) you can get a nice apartment for about 150 USD a month. There are many people who raise cocks for fighting purposes and fights are held pretty much on a daily basis in different galleras (cockfighting ring) in different towns as well as very informal right on the streets.
Anyhow, before you can bet on these you need to learn the lingo (i.e. Llevar, etc). You don't need to have a lot of money to go to the local Gallera as betting is small deals (i.e. a couple of hundred USD). You also must be prepared to fight your way out of people trying to rip you off either by saying they didn't bet with you (when they did and lost) or saying you bet them money when you didn't. If you're tough enough then you'll do OK, otherwise I suggest just stick to raising the chickens and letting someone else (Dominican) do the betting.
I grew up in this culture as my grandpa was big into gallos; That included having some of my own. He got out of this business a while back, but I've seen him have to kick some a$$ several times in my life because of people trying to cheat him. It's not for the faint hearted...
At the coliseums this is big business and many thousand dollars are bet every fight. I also know a couple of people who have lost everything they had due to this vice...