I hate to hear the term “blown”. That infers that something disentegrated in some way.
You also refer to gasket in the singular. With Subarus you never replace one; always do both.
If the gasket is “blown” due to severe overheating and so on then it may be time to throw in the towel. If the gasket is simply leaking or weeping then that is fixable. The 2300 sounds a bit high to me but that could be about right for you area.
I have stopped some leaking/weeping gaskets by bending a wrench or two and yanking down the head bolts a bit tighter. Whether your guy will do this I do not know.
Subaru has had head gasket problems since the mid 70s. The only period in which they were pretty much trouble free was from 1977 through 1985ish or so.