I may be reading this wrong, but New England has the "distinct" advantage with its hills that a cassette gets a fair share of wear across the cogs. Flat riders often find the wear is across three or four of the cogs, and usually the smaller ones which tend to wear faster anyway.
It might be wise in this sort of situation to ensure the bike shop has inspected the chainrings, and has taken the bike for a ride to ensure the rings are happy engaging with the new chain. There was a thread in another area of the forums recently where a guy injured himself badly (many stitched in his calf) after his LBS had changed out the cassette and chain, but had ignored the chainrings.