Around here if a Garand will go bang it will most likely be $800 minimum... WW2 correct $2000 min. Some of the rarer WW2 stocks are bring $400-$600 dings and all.
The cut OP you asked about is the op rod... the earlier ones had a square inside corner that would sometimes develop a crack so to prevent that a lot of them were reworked with a small radius ground there as all the newer ones had.
If you don't mind waiting and taking a chance that they'll ever again have much to pick from then a trip to one of the CMP stores to hand pick your rifle is a good way to go but recently on one of the CMP forums someone posted that they only had 30-40,000 left and being in crates don't know what condition... may be a bunch of drill rifles and again it could be like the Greek return CMP specials with near mint original metal. So watch the forums for info on what's in the stores.
Other than that you can search locally but if you don't know much about them it'll be a crap shoot or watch the CMP forums (there are Garands for sale regularly) and the sellers there for the most part should be able to give you an idea of how close to being correct it is as well as muzzle and throat readings possibly.
