I just shoot and have fun, worrying about cost is senseless . Everything costs money. I just took my girlfriend to shoot "unmentionable " rifles and the ammo bill was nearly $200 , because I didn't want to dip into my supply and I bought new ammo

if I have to eat Ramen for a week oh well
I'm never going to be like the guy I just saw at my gun club that drives out to the 100 yard line, posts a target, drives back, sets up his Hubble spotting scope and has a bolt action rifle. Proceeds to fire exactly 3 rounds, one every 10 minutes or so then packs up and leaves. I'd rather just find something else to do at that point if I couldn't afford to have a decent day of shooting
Life is too short
That said, Midway has a clearance on .454 round balls at 6 bucks per 100 so I bought 1000 balls. I should be good for 6 months of shooting with my Walkers now