First, there needs to be some explicit clarification about what "this" is. I would think it can't bear the Luminous-Landscape imprimateur without at the very least the consent of Luminous-Landscape. This automatically means that L-L would need to devote some resources at least to vet what's being done in its name, the prior issue for L-L I would imagine being whether this activity fits its role and purpose.
If it's not an L-L product, then I suppose one possibility is that it could revert to being a product of X members of the L-L Discussion Forum, with a very clear disclaimer about its relationship to L-L per se beyond that. Again something best discussed with Michael.
Then once it's "status" as a product is determined, something needs to be clearly articulated about its purpose. It could be anything, starting from a random collection of 150 images (if that's the number) which X photographers thought worthwhile enough to put into a book for others to see. That's the simplest reason to produce a book, but it's also why people post images on the internet. So is this "raison'd'etre" enough to grab peoples' attention and wallets? If not, then one is into thematic content and the editorial aspect becomes more pronounced and time-consuming.
If everything were really as simple as dumping a bunch of JPEGs into a canned format and letting the printer go at it, you may be right about the work estimate, other than for what I just mentioned above. But it may not be quite that simple. Have you seen the quality of blurb books? They're not bad, but there's better, and presumably there's file prep stuff which could be done to optimize the quality of what goes to blurb if they were the selected platform. Then you are into a question about whether all the submitters will produce quality and colour-managed consistent input to the printer, and who will make sure of that. With a bare minimum of specs and coordination you can produce a book which I expect will show what you get at that level of effort. You may not be totally thrilled with the outcome. Quality always demand effort and costs money - in just about anything I've ever laid my hands on, and I'd be surprised if this were an exception.
Let us turn to sales. How many copies, what profit and who gets it? If there were 150 contributors and each contributor bought at least one copy for the self-satisfaction of having a publication with a sample of their work in it, that would sell 150 copies. Maybe a number of people would buy several copies so they could hand them out as gifts on special occasions. So if on average we sold two copies per contributor, that's three hundred copies. And then there may be a number of sales beyond the contributor pool, depending on the marketing arrangement, which someone will need to proselitize and supervise, even if an outfit such as Blurb were to do the fulfillment. Over a period of a couple of years there may be several hundred more books sold, depending on the marketing, the level of interest and the quality (the product would need "marketable features" to pull this off). It's a competitive undertaking in an economic environment which really sucks and shows every sign of remaining that way for quite a while. Optimistically, there may be several thousand dollars of profit in it, but let's face it - this would be more for artistic emjoyment than anything else - which doesn't make it an invalid activity of course - but it does put a premium on quality, so one is back to whether a very non-organized, virtually random motif, implemented by Blurb, would really cut it, when one is trying to square the purpose with the product.