Sorry for the late response, I was in a trip. Well, whenever you want. My time zone is GMT +3, right now it's 18:17. I can play at any time from 12 to ~17 and sometimes, if I don't go out, all the way from 12 to 00.
It all depends on the amount of work. I was never really expensive with stuff, I don't like completely scamming people, but whatever you think is good for the project at hand, talk it over with the person.