Yes, UMPs (I think Unlimited Magic Passes) are LOS. The UMP is higher because it includes the waterparks, Pleasure Island, and Disney Quest, all for the length of stay. They cannot be purchased in advance without a package, thus no discount available.
Here's my situation: I have two rooms booked at CBM for four nights (Monday through Thursday). I am a member of Connections and I was going to purchase the 4-day park hopper passes with one plus through them for $194 (no tax or shipping). My kids like to go to the waterparks, Disney Quest, and Pleasure Island, but I didn't think the DTD resorts offered UMP.
When I found out they did, I called 800-223-9930 and asked them. They transferred me to the gift shop because that is where you purchase all passes. I was told I could be UMP for three nights/four days for $218 ($232.17 with tax). They said they could drop either the first or last day (just like the Disney onsite resorts do). They said they do not offer the advanced purchase discount on any of the passes.
For a difference of $38.17 per pass ($194 Connections vs $232.17 UMP), I think it is well worth it to be able to go to the waterparks, Disney Quest, and Pleasure Island every day.
I have the $20.03 rate for both rooms. I will be paying a grand total of $1099.34 for two rooms for four nights and UMP for four days for four adults. I think that is very good deal.
I hope this isn't too complicated. I you have any other questions, please ask.
Becky