If you are moving to the Sligo area, try Strandhill or Rossses Point if you can afford these areas. If not, Ballisodare is not bad. If I were to live in the Sligo area I would definitely prefer the above-mentioned to the town itself. It's a good area to live in; I have friends living in the Sligo area and they love it.
If you are looking for really cheap property that is a commute from Sligo, try Boyle, about 20 minutes down the road. Lots of developers stuck with dozens of unsold properties, reputed to be agreeing to substantial discounts on listed prices just for casdh flow. Not a bad town, if a bit parochial, but certainly very cheap. Carrick-on-shannon, a few miles further on, is a lot more expensive.