I've seen unlicensed guys go for $99 a room, but that's pretty crazy. $1.25 to $1.75 a square foot to scrape it and retexture is about right for a licensed and insured contractor. Price depends upon if the flooring is going, furniture and the height of the ceilings and the size of the house.
Remember to check for asbestos is built in the 1970's or before. Some textures are actually a stucco like cementious mix and those have to be skimmed or rocked over. Also if it has been previously painted they will want extra $$$ cuz that makes it harder to remove.