just to clarify, if you are going to leave your boat in the water for extended periods of time, you will need a barrier coat/bottom paint/antifoulant on the bottom, if you use a top side paint on the bottom of your boat, you should be fine unless you leave it in the water for extended times. How long are extended times? Depends on where you are, temperature and type of water you are in. I left my McKee in the water with no bottom paint from before thanksgiving till after new years with no issues, but the water was cold and growth was down. During the summer, two weeks and it would have an inch of hair and silver dollar size blisters on the bottom. If you leave a boat in the water with topside type paint in the water for long times, you are going to have blisters on the bottom.
As far as topside paint goes, I've used all kinds. Awlgrip is not the easiest paint to work with, their primers are hard as concrete, but it is a very good paint. Alex Seal is quickly overtaking Awlgrip and offers many more choices of finsihes and colors. Cheap paint vs expensive paint? Ask yourself what your prep time was worth.With the amount of time I spend on sanding and prep, its hard for me to justify cheaper paint that "May" not be as good
Keep in mind my personal boats are usually pretty ugly bare, chalky, unwaxed gel