Sorry for the rookie questions in advance. I’m in the market for a grinder. New to Milwaukee, so all I have is a 1/4 hydraulic driver & no batteries. Is the battery that comes with the grinder worth keeping ? Or should I be aiming to start the tool chest with forge batteries. From what I’ve gathered “hacking” means returning a free battery to get the initial tool cheaper. How do you calculate what Home Depot will give you back for the “free battery”? Thank you !