I believe Pete Hiatt coined the phrase " butt ugly" to describe the Ithaca doubles ( and M21s ) from time to time.
I wouldn't go to that extreme- but the guns cosmetic design may not be as appreciated as " prettier" guns.
The lack of comparative aesthetics might contribute to the lower demand , as value and utility are not always the key considerations for the purchase of " investment" or even "traditional" pursuits.
The practicality and dependability of the NIDs are without question, but for those that decide to use doubles and have the discretionary income to allow for more than just value, other amenities come into play ( feel/wood/look/wood/engraving even " panache")--- Ithacas may not put their best foot forward in these areas / hence lower demand/price for these very capable doubles.
best regards,
JBP
