If you didn't want the "cheap" plastic stock you most "economical" route would have been to buy a 700 BDL. By the time you pay for a Boyds (which is a budget option as far as stocks go) you would have more money into it then if you simply had of got the next step up right from Remington.
Since you didn't, then like the above suggestion, shoot it first - shoot it a fair bit - give it a good go and then decide if you need something else.
Being a 300 WSM I'm going to assume you plan on hunting this - a little over powered for simply punching paper - and if that's the case then maybe the factory stock is all you need.
Just because everybody and their dog says they are crap stocks, need to be replaced etc etc, it might suit your needs perfectly.