My Garand is one of the rebuilt 7.62x51 NATO conversions. It was equipped with a new commercial barrel, gas cylinder, op-rod, springs,etc. and all metal refinished with nice quality Parkerizing.
The stock was your standard GI wood, in decent shape. Although it's a shooter and will probably never have any collector value to speak of, I wanted to keep the wood as nice as possible.
When Reinhart Fajen was going under, I bought one of their laminated replacement stock sets for just under $100. It turned out to have some unforeseen benefits besides just looking nice.
Once the stock metal was swapped and the new rig was installed, groups with its favorite LC 68 match ammo shrank from 3 1/2" at 100 meters to just under 2". I can only attribute this to better fit and more resistance to changes due to heat and humidity.
A well-made synthetic rig should offer the same kind of benefits, and be lighter to boot. I have to agree that $200 sounds more-than-a-bit steep to me. But then again, the manufacturer had to invest in three complex and expensive molds (as opposed to one for an M1A), and most Garand owners/shooters seem to be traditionalist curmudgeons (like myself) to one degree or another.
FWIW, you could get a new walnut replacement set from Boyd's, Cabela's, Brownell's, etc. and some Accra Glass for less.