........... sorry to be awkward Donna, but there are so many things to be considered. I could give you a rough idea if the whole house was empty ........ cleared of furniture, carpets, people.......... but I'll bet that's not practicable!
What you need is one guy or two at the most to do a room at a time. Overall, this will inevitably cost more. With an empty (or new) house, they would flit around from room to room , with several walls on at once........... cutting down the cost.
I usually advise people to go down to their local Builder's Merchants and ask the guys in the yard who the local plasterers are......... one and two man bands :o)