40 hours you couldn't get out of the normal book?
“Couldn’t”? Irrelevant. I got them out of the product I bought. This is like asking if I could have gotten the same 2 hours of entertainment from a different movie, or watching the movie in a different format. Who cares? I enjoyed going to the theater and watching the movie, and it cost me about $5/hr. Therefor the money was well spent.
I don’t need the books at all to spend 40 hours telling stories in my own version of the world of Eberron.
EDIT: I should also add that I think low ROI is absolutely reasonable. Half the stuff in the B&G Eberron box is just stuff broken out from the main book anyway. With some shards that serve no game function etc. Something like this can certainly be good, but it would have to be useful, and yeah, offer good value.
The Mask of Nyarlathotep prop set is $139 and contains 109 actual clues the players can actually use in a gameable sense, plus some other niceties. I'd take 2 of these over 1 Gold Eberron box (which, given the price difference, is almost doable.)
And the Eberron box is full of props that are used to help run an Eberron game, from maps, encounter cards, etc, to handouts that are in-world items that contain useful in-world information. Not only that, but I have already used several individual things in the box for multiple different purposes. The rail station map has also been an unlicensed high rise tech garage and R&D facility, and the sky couch map has seen use to run an aerial chase battle, to set the scene for a meeting, and for an ambush the PCs turned into a counter-ambush (ie they ambushed Emerald Claw assassins as they tried to ambush the party’s noble friend),
and my buddy used it as a full sized airship in his game.
The encounter cards are fantastic, to the point where I’m going to make new ones for my homebrew stuff from now on. The magic item cards are great for randomizing common items taken from enemies or find in searches. The dragonshards are the least “useful” props in the box, and just the delight from my group when I handed one to a player in character as the NPC handing them one, and telling them they could use it to replace the rare ingredient in crafting a magic item of up to very rare rarity, or grind it up and use it in place of consumed material components at a very generous rate, was worth at least 20$, by itself.
Beyond that, the whole argument you’re making is spurious in any context outside your own very personal preferences. You don’t seem to grok the value of props that aren’t literal game pieces, which I find unfathomably odd. That’s just a case of incompatible personal preferences. I find a game full of
necessary props that a player needs to keep track of in order to succeed to be tedious, at best, while I find atmospheric props with occasional “useful” ones
very valuable for what they bring to my games.
Add to that the fact I can just bring the monster booklet, a few encounter cards, a couple maps, and some sundries, because it’s all broken up and individual, and yes, the box ROIs just fine.