I have a Barrett Mrad with a 7-35 Atacr that i bought with a 308 barrel so I could train with it and reload for it (175 match kings) easily.  I'm at the point where im interested in the next step.  I wouldn't have access to land beyond 1,200 yards, and most shooting would be done around 600 (Yes, 308 territory I get it)  I would most likely be running 190s or maybe lower 200 grain bullets but at 1000 I don't know if I would get that much more out of the PRC over the win mag.  I understand future proofing, and the PRC and Norma offer more in the heavy range, but I don't know if there is a clear benefit for my yardage.  Also an obvious consideration is cost, the 300 win mag and PRC seem to be somewhat similar in price for brass, the Norma is a bit more.    
I'm not opposed to spending more upfront (I have primers but I would buy brass and bullets), I just want to make sure it makes sense for what I'm trying to do.  Lots of people sing the praises of the Win mag, the Norma and PRC are both supposed to be great cases with very modern designs.  Everything I read talks about heavy bullets as their main draw.  Obviously I'm not being very concise, I will try to answer any questions.

I left my thoughts on your other post, but basically running the heavies, 245 berger/250 hornaday, the wm works better than the prc, lighten up to the 230 and smaller bullets and the prc is better... At 1000 yards..all of them will easily do it..even your 308 would do ok even if you rebarreled with longer barrel...Brass wise, to go buy brand new Lapua brass over the counter, yeah about the same price, if its even available for the prc yet, other wise you run hornaday until someone else comes out with prc brass... But to get decent usable  wm brass, there should be several makers, just gotta decide how much to spend...Norma is the same as PRC, expensive until someone else decides to produce it...WM has a huge advantage over the others on brass in my opinion...Everything else is the same with the exception of powder volume..some will burn more some less.. not sure the difference is big enough to matter, I run 300 rum, it runs 100 grains a load for the heavies on average.. But I wouldn't give up the rum for any of your cartridges, it out performs them in numbers, in brass makers and in fitting different actions...If I had to give up the rum, it would be the norma, but the brass makes it a worry for me if nobody else makes brass, someday the maker won't... My brother has a 338 laseroni he had built years back, he is out of brass for it and can't afford the price of new brass, evidently it is stupid expensive... So I invite him shooting and he never comes, all because he went with the new wonder cartridge and got smoked for it...

Heard 300wm doesn't have enough room to run the eld bullets the PRC does.   Norma had some issues with inconsistent burn at angles.

PRC got soccom contract so I don't feel like it's just a fad

Yeah I'm looking into a long action caliber to get myself into.  In the very early stages of my education.  .300PRC seems to be very interesting

.300 WM is an older design. The belted case isn't optimal in my opinion, and the SAAMI throat will limit space for longer bullets. .300 PRC is by most accounts a modernized WM, designed with a similar case capacity but with a throat long enough to fit 215-250 grain bullets. .300 NM is a little bigger than the PRC with its Lapua Magnum case head. The case capacity is just a tiny bit higher, and it can achieve slightly higher velocities.

Based on your needs a .300 WM could do everything you're asking. I'd still go with .300 PRC if I were in your shoes. It allows you to have a little more reach if you ever had the opportunity to shoot further, and there really aren't any downsides I see to going PRC. .300 NM is only incrementally better than PRC and it comes with a lot of costs in terms of action availability and component costs. Unless you really needed a mile+ rifle I don't think I'd go for the Norma magnum.

There are some good reads on snipers hide if you google or go search there on this exact topic.
They have some amazing insight on the subject.

I have been invested in 300WM for more than 20 years so thats why I still have it.

Recently I have been shopping to get into something else and I settled on 7PRC based off of what I want to do.