$600 isn't too bad for a WWII era Garand, but with all firearms its CONDITION, CONDITION, CONDITION.
Rack grades will be shootable, but I have recieved more than one Rack grade that required a barrel before they would do anything beside despense pills.
Service Grade is a better way to go, but again it's a roll of the dice where you could get an exempalrly rifle or one that just meets the "Service Grade" criteria.
IF the barrel is "in the white" and of the correct date and manufacturer for the serial number range, then I would buy it for $600. In fact, if you pass it up please let me know where it is and if possible maby soem of the identifying markings.
If furniture is a concern, I have a dozen or more stocks in various stages of finish that could be had VERY resionably (each) or new furniture is made daily by Boyd's, Weineg. and a couple diffrent synthetics are also available.
IF it need or you want a .308 barrel that'll be ~$200 (I've got an excellent used bbl $125.)
The Garand bubble has pretty much burst leveling off the prices, however they "don't make 'em anymore" and they ain't gett'n any cheaper. Do it now, and turn a buck later if you need to.