Having organized a couple of trips, I feel compelled to defend the LDS. There is a lot of work behind the scenes that goes into setting up travel. The shop has to do some research, identify desirable operators and lodging, check them out for reliability, and book the spaces. There is a considerable amount of money at risk, and people aren't reliable. The trip I organized last year, I had every spot spoken for BEFORE I committed my money to book the ten spaces. Within two months, I was down to three people out of the original ten who had given me their word. I was on the hook for about $10K. I wouldn't be surprised if the LDS adds something to the price to cover the risk of someone backing out and not paying.
In addition, at least with the LDS-organized trip we went on, they facilitated everything. If anything went wrong, they were the ones scurrying around to make it right. If you travel alone to somewhere remote, you'll be the one dealing with the lost reservations or the broken boat or whatever issue comes up, often with no financial recourse other than what you can strongarm out of someone.
Personally, if I want a trouble-free trip where somebody else has taken care of everything, made all the arrangements and is prepared to stand behind what the advertising offers, I expect to pay a bit for all that service.