Hook Boutin, a legenary Service Rifle armorer. He's still building rifles in I believe Arkansas even though he must be in his 70's-80s. Think he call's his shop Old Corps Armory. The street price to build a NM Garandis anywhere from 2500-3500 dollars for a ground up build. If you intend to shoot it as a serious competition rifle ( If it's been reworked by SAI it's a shooter so shoot it) take it to a gunsmith who specializes in Service Rifles and have it gone through. They'll gauge everything, rebed, recut crown if required, check trigger for sear engagement, unitize the handguards,etc... If your barrel is good it won't be very expensive and the rifle will shoot to the level of the barrel for accuracy as I don't know how hard you hold or how many rounds are on the barrel. Isaac McCaskell (Cassatt Gunsmithing) in South Carolina, Fulton Armory in MD, Dean's Gun Restorations TN, Match Service Works Ronnie Morris TN, to name a few. Those smiths you can ship to, some of the older guys are only taking work if you can drop it off. Doc McCoy passed away and Clint Fowler just retired. So my opinion is your ahead at $600 and even if you put another $400 into it (if the barrel is good. Good=MOA or better at 600yds) your still ahead for a NM competition rifle, not a collectable rifle. It isn't a low number Winchester with Keystone springs and all or Gas Trap. Hope this helps.
Tom