In order to give a price the following must be specified

1. the type of drywall used on walls and ceilings .
2. screw spacing and overlapping is the most important part of pricing due to the labour costs of doing a professional job.
3. It must be specified that all gaps must be pre-filled before taping and finishing starts and all areas for corner bead be sheeted or pre-filled square in order to not have a hollow corner.
4. corner bead and types of trim must be determined, as the cost of the corner bead can double and the type of application method can double in cost as well due to mitring corners and filling the corner bead.
5. The taping method should comply with the Canadian standard and ASTMs: enough compound to fill the voids
6. the type of filling compounds being used, finishers like to use the light filling compounds because they are much faster to sand down but cause many problems because they create a very soft and easily damaged finish. the harder compounds are more suited to high end homes and construction projects. 
7. the level of finish desired 1-5 or even the level 6 using rod and feather edging to create a totally smooth flat surface.
8. we cannot determine how much pre-filling will be required to accomplish a quality job until after the home is sheeted we can only give an estimated allowance for time pre-filling because time can vary from 1 hours work to 16 hours work due to framing being out of plumb, square and level. A price per hour should be established as well so this process is not overlooked to maintain quality workmanship. this process is the base for all finishing

From a low bid to a high bid costs can easily vary $5000 on every 10000 square feet depending on materials and labour.

Drywall

Plaster Board 

Plaster Board with Drywall finishing

Plaster Board and Plaster finishing

Veneer Plaster (One Coat)

Veneer Plaster (Two Coat)

Venetian Plaster (depends heavily on work areas and type of finish)