I had just searched for Newtownabbey on propertypal and like someone said they looked lovely and unbelievable prices, but with a quick search on googlemaps you could see flegs. It may mean the increase of 20K to the house but it's worth it in the long run and these houses I assume are more likely to keep their value that bit better.
It's a hard one to decide to buy something cheaper or buy a house that would be an extra 40/50K but that I would be happy with for years.
Go and look at the streets you're considering. In Belfast there are flags everywhere, and a street could be on the edge of a dodgy area. However, you do have to ask yourself why the prices are unbelievable.
Buy somewhere you want to live and you're happy to drive home to. It's amazing how quickly you get used to the mortgage payments.
Jordanstown, just outside of Belfast no flegs, great area, Loughshore at the bottom, bars, restaurants, cafes and great location to get to work, takes me 20 minutes in the morning and 15 mins on the way home... good schools also... cycle/run/walk path straight into Belfast