I think I can shed some light on this:
There are three versions of the MRAD:
• MK22: Essentially the mil-contract MRAD. Has special engraving, bespoke cerakote unique to the mk22, color matched bag rider and of course barrels, mags, bolt heads, etc if you go for the full deployment kit.
• MRAD: User interchangeable barrel capability. Folding stock.
• MRAD SMR: Same as MRAD,
without the barrel change capability. Non-folding stock.
If it were my money and I didn't care about being "clone-correct", I'd buy an FDE MRAD in 6.5 CM and then get a couple barrel kits in calibers I'd actually shoot. The MK22 deployment kit comes with a 308, 300nm and 338 barrel kits. I'd personally rather shoot 6.5 over .308 and I'd never touch the 338 kit.
I'd argue there is no fundamental benefit to the MK22 over the MRAD unless you care about the markings and cerakote. They are functionally the same.
Now, you've asked about other rifles to get into long range shooting:
I'm a fan of anything AI. I've owned an MRAD and have had several AI's of every variety. The quick barrel change system in the AI is the absolute best in the industry. It's fast, repeatable and durable. Not to mention the accuracy is world-class. If you don't need to shoot magnum cartridges, I'd pick up a used AT/AXSA/ATX for at or under $5k. You can buy a couple barrels and a high end optic and come in well under $10k. If you want to shoot magnum stuff, you're going to want to go with the AXMC or AXSR. For under $15k you can certainly get the rifle, a couple caliber kits and a high end optic.
or you can spend $15k-$16k on a MK22 deployment kit (no optic) which is essentially a $6k MRAD with x2 extra $1,500 barrel kits and a cerakote job.
Eurooptic has an FDE 6.5 MRAD for $5700 right now:
https://www.eurooptic.com/Barrett-M...Flat-Dark-Earth-Cerakote-24-Fluted-Bbl-1.aspx