Since I do my own Garand work, I haven't kept abreast of the retail market for gunsmithing this rifle. Brownells keeps up a survey of gunsmithing charges. From that, Parkerizing itself should be between $95-$145. Clean, oil and inspect, $50-$100. Barrel replacement will depend on the cost of the barrel itself plus the format of it. A new Krieger heavy weight stainless barrel with breech end contouring but no chamber cutting will involve stock modification as well as the chamber work to fit. That's not cheap. I think the best bargain is the CMP price on new Criterion standard weight barrels for under $179 (most places sell if for $250) that have lapped bores, are standard weight, and short chambered so that only need final cutting to headspace. Otherwise they are basically entry level match grade quality, are more than up to standard weight Garand potential and, if you don't bed the stock, qualify for the as-issued rule matches and would be an excellent choice.
You then have to install and chamber the barrel. Brownells has chambering and fitting a barrel at $150 to $250. However, if someone is set up to do Garands, specifically, and considering the Criterion barrel is already short chambered, I would expect the bottom number. I would also expect that if you gave him all the work he might come up with a package price.
So, with barrel cost included, I would guess you could get it done for less than half what you were quoted, based on Brownells numbers. But, again, if you deal with someone who specializes in that rifle, it could be less. I would get a couple of quotes.
Note that, unless the rules have changed since I last looked, you can ship a gun to an FFL holding gunsmith directly, and he may ship back to you directly without going through an intermediary for transfer, as ownership isn't changing. The shipping will set you back something, though.
Also, you should check out the CMP forums
. Lots of guys there are doing Garand work, specifically. You'll find information about inspection and gaging there, and can learn to do that yourself to save some money.