Between .50 - 1.00/sq. ft. depending on how detailed the job is. That will pay for your paint and labor. The average house will cost $1500 to $3000 for 2 or 3 days work. I paint houses so I hope this helps.
Well, I have never priced that in sq. ft. because it is so hard to do that way. I look at the amount of ladder work, boom, scaffold or whatever your means are to get to it. Amount of time you think you will have in it plus the material. If you don't get $30 - $50/hour doing it you will lose. Again figure 2- 3 days painting in most cases. 8 hours/ day. Figure your total time and material and bid it that way. Most people frown on an hourly rate.
my brother owns a painting company and does all sorts of work. i can talk to him and see what he says about this. also where do you live? he does free estimates so if you are somewhere near the cleveland area, he probbaly could come look at it and tell you how much it would cost ya. he is reasonable in pricing too lol. xsorry fro the plug, but figured it coul dhelp both of you out.