Apprx how much will a painter charge to paint the walls and ceiling in a 20x16 room with a cathedral ceiling and one wall mostly fireplace and window. Also a 14x14 two story foyer. Walls and ceiling. What can be done to paneling before painting to make it look like sheetrock?

Around where I live, the cost is about .70 cents a square foot if the paint is applied with a roller and the area to be painted is perfectely flat with no texture. This does not include the product used. But, the price may be different where you live. You might want to call around and see what painters in your area are charging per square foot for the area that you are describing.

Applying a spackling compound, sanding smooth and sealing with a primer (a couple coats) should do the trick to be able to paint paneling. You also might want to roughen up the paneling a bit with a palm sander using a 120 or 180 grit abrasive paper (sandpaper) so that anything painted on it is more likely to stick to it.

You might also find some helpful tips on the following site:

How to Paint Over Paneling