If you're happy with Cork St, why not look around Dublin 8? Walking distance to town, nice mature, residential areas (OK some parts, not all)...
Granted not many new builds, but some great second hands in great nick for your budget.
I got lucky last year, and got a fab second hand, 3/4 bed, ready to move into, very little work needed in the area, only 20 years old, so no gas/ electric/ structural problems.
I would never have considered a new build though....estates are too far out, estates can be unfinished, you don't know what the estate will be like in 20 years time, could get taken over by the council, bad residents, etc, lack of facilities, transport, etc. Also, unless all the fixtures and fittings are included, can end up costing you a lot more when you decide on what kitchen, tiles, etc you want. I got all the kitchen appliances, curtains, etc included in sale of my house...have been changing bits slowly as I go along, but was under no pressure on moving in straight away! Also, think a lot of new estates really lack character and personality! And can be structurally really crap!!!