If I were you, I would buy this:

http://griffinhowe.com/riflemoreinfo.cfm
Griffin & Howe - Mauser - .300 Wby Mag caliber - $4,750.00

and have G&H rebarrel it to .375 H&H. Have them quote your a price on the rifle with the rebarrel job included. In the past they have come off their asking price on the rifle for me, presumably to get the rebarrelling job. For approximately what you want to spend, you would have a first class custom rifle, superior to either an off the rack Model 70 or a used Dakota.

The last time I checked, G&H was asking $7000 for a custom stock, so you would be getting a complete rifle for less than the current price of a custom stock.