Flooring comes ready to fit, it does not need a carpenter . It just slots into position, a competent hanyman or DIY person shpuld be able to lay it The main job is getting the surface ready once that is done the floor boards just slot into each other.
Sorry I assumed the poster already had the wood and just wanted to know how much a carpenter would cost. I have no idea how much a carpenter in your area would cost but the last time I had this done, we bought the wood and underlay and it cost £100 for the guy to put the floor down.
There's been a lot of advertising for ratedpeople.com recently which is like a trip advisor for tradesmen. Seems like a very good idea.
It's been a while since I lay them but when I replaced a simple 12' x 10' room's floorboards the oak boards cost me hundreds without costing in my time. You need to give more details on what you are planning to use before a ball park figure can be ascertained. Including any finish/protection you have in mind.