cabelas is good for the the rest of the outdoor stuff - camping, hiking, paddling, clothing etc. which i wouldn't buy from a fly shop anyway.
and as to the low income up there - i find that untrue some. i worked for a pittsburgh bank and we visited up there regularly. there's a whole bunch of old money up there, so much that we had a Wealth Management office built up there for people to deposit and pick up cash, help with HNW mortgages etc.
plus you have the 'summer crowd' .
LL Bean have opened some smaller stores in MA in the last few years. They have Orvis rather than Bass Pro in their sights i think.
If i had to guess i'd say their size is about 20,000 sq ft. I think the comment about the decline of big box stores is dead on - amazon and ebay is killing em.
I know the manager of dedham MA LLbean and they are there to build brand image, provide personal advice and introduce people to outdoor sports, and if he's honest to leverage their catalogue...