When I say good paint, I mean Behr standard paint, not that stuff with primer already in it. I've tried that stuff and it's too thick, too sticky, does not flow well, and I still have to use two coats, and it's way too expensive. Use their standard paint. That's good stuff. Then pat yourself on the back for saving money.
Also, remember, if your interior walls have already been painted, they don't need primer except for bare spots and exceptionally soiled or stained spots.
Buy a Starbucks with the money you save.