I have absolutely no doubt you can find apartments for $200 p/m, you can do that ANYWHERE in the country. As it goes I used to pay RD4,000 (near enough $100) p/m in Villa Mella, capital, several years ago when I was going through a weird spell in my life, albeit a brief spell thankfully. This was for a 3 bedroomed house, but I would never in my wildest dreams recommend it to anyone, yet alone a foreigner of sane mind, so I don't, because the information is useless, and to recommend the place is irresponsible of me, but it is there all the same.
Something is better than nothing is not always the case my friend.
what would be the average rental cost for expats in the area? Consider this and then you have a comfortable average as a number to hang out there as a typical rent, not the lowest rent you can find on the market, the info is useless, expats don't tend to live in these properties, do they. Well other than your next door neighbours friend, until last year when he moved onto your gated community with the boat house extension.
Carry on by all means, but I think you'll find the same reception as last time if you do.