...they are pricing themselves out of their niche...
I don't disagree, the price does seem steep but it's also supply and demand. This foam is a niche within a niche.
To be fair, the sheets are larger. (30x40)
Sure, dollar tree foam is stupid cheap, $1 a sheet, but the dollar store foam isnt the quality of the FT waterproof board.
I'd compare the regular FT foam I've had in the past to the heavier wal-mart stuff quality wise, and the FT foam is much more well suited for flying at about 1/3rd less weight. That heavy poster board is $3 to $4 a sheet about anywhere. That puts it right on par price wise with the new thick maker foam per sq inch.
In past custom builds I've used the heavy poster board in places where I've needed additional strength. I'm hoping, for me, that this new maker foam does that same job with less weight, but that is still TBD...
Working on a build to test it right now, will have some pics up soon...