I have been developing freelance in PHP for 3 years. I am currently working in Baker Street, and charge an in-house rate of £18 an hour. Note, this is with plenty of experience, a BSc and in the big city. Clients have been less willing to put their fingers in their wallets recently, with the downturn.
Agencies will laugh at you if you have less than a years experience and ask for E100+. I have been freelance in java as well, thats where the real money is - and where the real clients still are, but PHP is just so nice!!!
Be realistic, you dont want to scare people off.
But stick at it!!