Big glut of houses in Boyle, and still building. One new estate being built on South side of town has reputedly had NO sales yet, and several houses completed or nearly completed. Should soon be possible to buy a lot cheaper than asking price if you need a home there, but "invest"? No, in my opinion.
Best bet in that part of the country, if you want a tip, is probably Drumsna, just across the Shannon in Leitrim, just off the main Dublin/Sligo road. Dromod, a few miles away and also on the Shannon, is a very similar town and prices are strong -- a smallish 2 storey detached house close to the river went for 425K this week in Dromod. Drumsna was almost a clone of Dromod a few years ago, but has been overlooked and prices are way cheaper. Only difference is it doesn't have a railway station. Worth looking at though -- not too much for sale around there but some good value.