RUN AWAY FROM THE COMPUTER WHEN YOU HIT LATE NIGHT PANIC MODE! I'm not sure if there is or isn't a cap or if this was worth it. I do know the London Pass website on sale was more expensive than visitbritainshop is. I keep calling the listed phone number and it says the line is busy, call back later. I'm disappointed in myself, but I need to move on. Thank you again for everyone's help and sorry about the whining. If you are in London the week before the cruise, you will know it is us as we will be the crazy family running from activity to activity.
Keep in mind you get the guidebook and you to avoid waiting in lines. That alone could make the card worth it. In the grand scheme of things, the $15 dollars you saved or didn't save on the pass is no big deal. How much is this vacation costing you?

And you won't be the only family running around like mad-tourists trying to get all we can out of your time in London!
We've already decided we're going to run ourselves ragged in London...and we take comfort that we have a sea day on Sunday where we can sleep late and recover from jet lag and lack of sleep etc.