I just did a quick calculation--I am getting around $5k for .22LR alone.
If you are loading .45 acp for $3/50 that is $7665.
If I was retired, and had no other interests, I could find time to put together 350 rounds per day and shoot them.
Without rushing things (meaningful practice) I usually go through 100 rounds per hour. I guess I could rush things a bit and go for 150...especially if I had a whole bunch of pre-loaded mags...but that takes time too, and I prefer to shoot 5 rounds at a target, get a look at the results, and try to shoot each target to the best of my ability.
Practice makes perfect...but only if you practice perfectly. Hard to do that if you are just trying to burn up "x" rounds and get to picking up brass and getting on to tumbling, etc.
Yes, I would also need to tumble cases and cast boolits. I realize that I could do a week's worth at a time...but the hours all add up, whether once a day or once a month.
Not to say that this would take up 8 hours per day, but it sure looks as if it would start to resemble a full-time job after a while...7 days a week, every week, for a full year.
If you have the time, the resources and the inclination, and it doesn't become a chore, I wish you luck.
I am no world class shooter, and never will be. FWIW, I am 56 y.o., and I also had spinal fusion surgery almost six years ago... and may be having another soon.
I have also made a fairly significant improvement in my shooting in the last five years, and for me the best ROI was shooting once a week for an hour or an hour and a half, taking my time, and shooting 100 rounds of .22LR to every 50 founds of CF ammo.
In reading your post, I'm not sure if it is your goal to simply expend a bunch of money, time and ammo...or to actually improve your shooting in a meaningful way. If the latter, I think that an hour or two per month from a good instructor, added to some meaningful practice, will yield better results.
Best regards, Rich