Depending on how much you shoot, it may or may not be worth it to you.
Loading 300nm and 300prc will be about a 15cent difference per shot. Then there's barrel life. Everyone will have their own opinion on this, but generally, 300nm is around 1200 (sometimes less) and 300prc is about 1500. AXSR barrels are $900 or so. So, that's another 15cents per round difference.
You'll be looking at an extra $0.30 per trigger pull shooting norma on average. That's a savings of $300 per 1000 trigger pulls. Obviously this isn't a perfect calculation and I'm sure others will come up with something different. But it's fairly safe to say that 300prc is about $100-$300 cheaper per 1,000rnds.
To some that's worth it, and others its not. You also have to factor in the cost of a new bolt if you don't already have the magnum bolt and if you don't shoot a ton.....there goes all your savings or you may even be negative dollars spinning up for 300prc.