I was not expecting throw away brass but those custom made solids can't be cheap. Custom primers probably cost more than .50 BMG primers. They are going to use lots of powder and then amortize the reloading equipment costs, barrels and reamers. It all adds up.
For my 338 RUM, brass was about $1.30 but its 300 RUM and needs neck expanding and shoulder bumping. Not a huge deal but I hope the primer pockets last for at least 4-5 shots for $0.26-.33 a shot for brass. A Berger bullet is about $0.80. A primer is about $0.04. Powder is about $0.38. If my barrel lasts 1,300 shots, that's $0.50 each. Dies amortized over 1,300 shots are about $0.15, maybe less if I go through two barrels because i just got a $60 Hornady die set, a Hornady modified case, a $14 Lee crimp die, a $20 redding body die, a $24 Lee die set for neck expanding, a few spare expander stems and I'm going to get a Lee custom collet neck die for $75. I think that's $2.13 per if I get five loads a case. If I get 10 loads a case or amortize over 2,600+ rounds and two barrels, I'll be closer to $2.00 per.
I know that is cheap for entry level ELR. More mainstream cartridges like 6.5 Creedmoor and .308 cost half as much to reload because brass life is better, barrel life is better, you use less than half the powder, a Berger 140 is about $0.45 each and since brass is easy to find, you can use a pretty simple reloading die setup instead of buying stuff to neck up and shoulder bump and different stuff to use once the case is formed and fire formed.
You have to deal with large size die bodies, custom dies, custom reamers, custom brass and your barrels probably shoot out pretty fast by comparison. I'm still thinking $20 a shot isn't too far off.