Each week Kroger seems to put a particular cut on sale for 2.50 a pound. Sometimes Chuck. Other times sirloin, bottom round, etc. I usually buy a couple roasts of whatever is on sale to vac seal, freeze, then use later for various purposes. Have Kroger in your area?
Also, Gordon food service sells giant vac sealed whole cuts for decent prices if you wanted to grind alot in bulk.
I usually don't because I catch sales, but I would happily pay upwards of 7 dollars a pound for my own ground beef. The end result and especially texture is worth the extra price. For things like tacos or casseroles I may reach for one of my lesser blends, but honestly I think you will have a hard time going back to preground beef after having a fresh ground burger. The texture more than the flavor is what sets it apart.
If you are really trying to do it on the cheap alot of butchers will sell beef fat for next to nothing. You could grind that in with whatever cut you want, and get some good results.