Quoted from snaroff:
They did several runs. Over 5000 manufactured, which is fairly high. Resales are often very fairly priced as well.
The fact that they made 5,000, or 8,000, is irrelevant to whether a Vault makes sense. Unless you think Stern runs Vault games so that everyone can get a chance to play its rarer games, instead of to maximize profit and fill the line during down-periods. In the case of LOTR, despite a very large run there's enough demand that even routed examples go for more than $5k. Tron may go for more (though I'm not even sure if that's true any more, LOTR keeps creeping up in price) but with only a fraction of the number of games made, so there's plainly more demand for LOTR. If Stern is looking to make more Vaults at this point -- and who knows in the pandemic era, they may well end up with a backlog of new game designs they could run and have no time or interest in doing Vaults -- LOTR is still right at the top of the list of logical games to run again.
The question as always is whether they could make the licensing work, and it's still the case that no one on Pinside knows anything about that. Though if someone pushes forward and tries to license the "The Art of Pinball" playfield shown in this thread so it can be reproduced and sold, they may learn something about the state of the LOTR license through that process. Of course no one with any sense would expect the results of that conversation to show up on Pinside, but if they can get approvals to move this project forward that will suggest that licensing for a LOTR Vault is not a lost cause.
Either way, @scott9, looking forward to seeing you finalize that new design, which will be just as cool whether it remains a one-off or makes it into production.