Our moto: "You can save a lot of money doing the work yourself."
We had a plaster contractor from Appleton look at the walls and ceilings in the house (3,000 sq. ft). He wanted $26,000 to put 1/4 drywall over the ceilings and walls. Another plaster contractor looked at the house and said, "The walls are in fine shape--repair the cracks and skim coat". Having the second opinion saved us $25,000.
It hasn't been easy, but my husband tackled each room. If you stick with it, it takes about a month's work per room. My husband put up new drywall ceilings. Each crack was repaired with Durabond plaster and flexible web tape. Sanded, then ready for skim coat plaster. Then sanded, then second layer of skim coat plaster. Then sanded, and evaluated for areas requiring more plaster, then sanded.
After the plastering was complete and the woodwork washed and taped, Zinzer 1-2-3 latex primer over the ceiling and walls. Two coats worked best. First coat really sopped up the paint, and of course second coat much less.
Two topcoats of latex. The kitchen is Valspar "Aged Photo" Tan, the dining room "Flaming Sunset" Red, "Bewitch" in the library, and "Barely Brown" in the Office/Music Room. A custom mix of "Barely Brown" and Brunnette" is the living room color.
We topped off each room with a double molding my husband picked out. The molding was the last thing installed in each room.