Pricing questions never end well here---so before this turns into a 'roast the new guy' thread, Iwill offer the following safe way for you to figure this out for yourself---
You said you are experienced---so you should know how long the job will take to bed/coat/sand---
my guess--two full days---one half day---
How much per day do you need to make payroll---cover tools /truck and other business expenses?
How much time for selling---collecting the bill--call backs? Another 1/2 day?
there is three full days if I was doing it----how much per day for you? What money above that amount do you need for profit and expenses?
That's your number----going rates stink as a method of pricing---If I told you $15 a sheet and the job has soffits and closets---is it the same price as the room next door that is just a big box?
What if both rooms are identical and one room is hung by a pro and the other by a beginner?
Then there is the customer----will a pro painter take over when you are through? And do the little touch ups that are so often needed with new work?
Of is the home owner painting and then call you in to do touch ups when he's all done==then whine that you owe him a paint job?
By the way----sell primer with your taping.