Jennifer, the bigger question is if you can afford cheap paint? What is the price of having the painter come back a year or 2 sooner? And it's not just the price of his time but the inconvenience you will have.
When we had to have out place painted due to a move and I hired a painter, he specified that he had to pick the paint. I knew his reputation and didn't argue. He painted, with a brush, the whole place with one coat. It looked as good or better than it would have looked if I had used a cheap primer and 2 coats of paint. I'm sure that it lasted longer, too, but it was also a saving to me in time and material--looking at the total cost--to have him do it his way. We had the normal gummed oatmeal Scotchies and crayons on the walls before he started.
It took me some learning, but I found out many times over the years why cheap paint costs more than good paint. I like Benj. Moore. Others on the board like Sherwin-Williams. Your local paint store probably has as much to do with this as anything. Mine has been great with their quality level and price suggestions and even told me that I was buying more than I needed. That your store will do that is as important as the brand of paint that they carry.