The purpose of my future 50 BMG semi-auto is not to do a sniper kill from 1,000 yards but just to totally get my rocks off..... to fill my body full of adrenaline while I pop off rounds from a shouldering position!!!!! Just pure stupid pleasure!
That'll be fun the first few times you do it, but you'll quickly tire of holding a 30 lb rifle up and firing off very expensive ammunition at cans, melons or dirt birms a few yards away. Believe me, that's not even fun with 5.56 or 7.62 NATA after a short time.
If you own a .50, you'll want to see what you can do at 1,000+ yards. Why handicap yourself with one of the least accurate rifles, cool as it may be?
Remember, the M82 was designed as a DMR rifle for primarily anti-material use. If I was trying to stop an inbound hostile vehicle at a couple hundred yards, yeah, I'd prefer the rate of fire the M82 offers over a single shot. But for long range accuracy work, there are far better choices.
My suggestion would be to get an M99 or AR-50 or some other $3k-$4k rifle, plus a 7.62 autoloader the likes of an AR-10, FAL, etc, and spend the other two or three grand on optics and ammo. You can set yourself up pretty nicely for the same price as the nifty but somewhat useless for civilians M82.
I'm only making these suggestions based on the fact that the overwhelming majority of us on this board are working class, and I have known more than one such person who later regretted spending so much on what amounts to little more than bragging rights after the initial wow factor wore off.