The office is the room I use. It stays at least 70* , but I can also add heat by hanging a 250 heat light in here. You also want a room that is closed off and does not get a lot of traffic. You should be able to find one for that amount easily, if you don't buy a turner, but you will eventually.
My thing is I'm never guaranteed a good hatch or fertile eggs. So if I set too many or too few I won't get what I need. Plus right now I've chicks I don't want. I'm working on getting more Lavs EE's.
No one around here will buy chicks so I sell them cheap or trade or give them away. Which reminds me I need a chain saw. Nothing big or fancy or to take down huge trees. I can't cut 4" to 6" around trees by hand.