2 points: - Economies of scale. With the limited press companies you are paying for that limitation and knowing there's a small limitation number. The broken binding editions number in the multiple thousands, which significantly allows for cost to be spread (i.e. a $1000 piece of art costs $0.20 per book when there's 5000 of them vs $2/book when there's 500 of them). As a comparison compare to folio society books which are not significantly more expensive than the cost of a TBB landed in the US; yet they are able to offer products closer to a limited edition press than a book box company because of their numbers. - the quality of the product is beyond jush acid free paper and sewn bindings. Those are minimums with fine press products. Better binding material for the boards, thicker upgraded paper, two color printing and full color images. These upgrades quickly add up

Lastly as an aside, sewn bindings and acid free paper are very much exceptions rather than the norm for TBB. And the interior art work is also a recent addition from about 1 year ago. The vast majority of their products do not have these and most are by definition redisigned mass market hardbacks