I would avoid a cordless, but it can be done. You need to find something with a high amount of torque. An impact driver set to normal mode might do the trick. Go with the highest voltage you can afford in your budget, and keep spare batteries handy.
I use a cheap Home Depot hammer drill, with hammer function turned off. Mine has a threaded speed adjuster on the trigger that allows me to dial in the right speed. Its a plug in type.
I just milled for the first time last weekend with the new corded porter cable variable speed drill that I bought at blowes. So much easier, don’t think I would have survived hand milling the 25# of MO for my EBW brew day courtesy of “Experimental home brewing” I agree, get a drill
Edit: mine was right around $75 after taxes
I use a cordless 18v dewalt also. Put it on a monster mill with set on #1 for speed. Only get maybe 3 uses before having to change battery. I would by a corded drill with variable control if you have a plug near by. I use the dewalt just because i had it for honey dues and such.
I switched to a corded drill and it works much better. The 18v cordless struggled as I crush very fine. The good thing is you can get corded drills at flea markets and such for a few bucks.