Unless you plan to regularly hunt big game larger than elk at ranges exceeding 400 yards, there's not much reason a 6.5 won't do you better.
The 6.5 will have more or less the same trajectory as the .300 with much less cost, much less recoil, better barrel life, and the Bergara will very likely shoot better than the M700. The only down side is that you have less energy on target, but a 143gr 6.5 ELDX or 140-147 ELD-M (I hunt with ELD-M's) is more than enough to take down elk, deer, antelope, caribou, etc... out to 300-400 if you can toss one in the boiler room.
You're still running .6-.7 ballistic coefficients, you'd be at 2700-2850fps (Very comparable to heavy bullets in a .300wm), but instead of burning 70-75 grains of powder you're looking at 41-45. Match ammo and ELDX hunting ammo is everywhere for the 6.5, I'd hazard to guess more prevalent than .300wm. The long and short of it is that the 6.5 can still be very effectively used for hunting, while being a vastly superior PRS cartridge (recoil recoil recoil! spotting hits/misses is huge). It might not cost as much as what you have into the 700, but I think the B14 is a better rifle. So part it out if you have to, but I think you'll be ahead in terms of comfort and frustration (accuracy) to hop on the B14. Don't take it in the shorts by any means, but for what it sounds like you're wanting to do, the B14 is a much better choice.
