We have part-time retired to southern Maine. And we are aficionados of the lobster roll. They come in all shapes, preps & sizes up here.
Cheapest--and pretty good in its own right--was from the Shore Market in York, probably 3 oz warm with drizzled butter on a toasted split-top hot dog roll, $16.99.
Most expensive--but totally nirvana-esque--was at least 6 oz of chilled, dressed lobster, mostly knuckle & tail meat--on a large, toasted, slightly-sweet Hawaiian-style roll at C Salt Gourmet Market in Cape Elizabeth. Sprinkled with minced scallions. $34.99...but oh, so worth it!
FYI...up & down the seacoast, in between are various incarnations of size, mostly in the $25 range.
Also FYI...the Maine Lobster Outlet in York on Rte. #1 currently has steamed, whole lobsters to-go at a season-low price of $6.99/lb. In April the price was $13.99/lb. Might have to partake today or tomorrow before the market goes up again.
My favorite size is 1.5 to 1.75 lbs., perfect for tastiness & tender meat. Starting with the monsters at 2# and over, the shells are hard to crack, and the meat gets tough.