Park to Park access worth it at Universal Orlando? Suggestions for budget hotels?

I was sitting here in front of the computer trying to decide about the need for Express Passes as I am trying to plan a trip before school starts when I came upon your website! Looks like I will save that money to spend on other things per your suggestions. I will be in the Orlando area late Saturday night (8/27) as we are doing the driving adventure from Pennsylvania. My thought was to take a quick trip to the coast on Sunday since we will be getting in late on Saturday then hit Universal Studios/Island of Adventures Monday and Tuesday after a good night rest on Sunday. I was also wondering if purchasing the Park to Park pass is worth the added expense? My kids are 12 and 14. The one thing my youngest made clear is she wants to go to the Three Broomsticks for lunch.
Due to several major events, the three of us we will be traveling on a tight budget. Still trying to decide the best choice for accomadations so any suggestions, in the park vs. stay out of the park, or any other suggestions to make the trip more enjoyable while staying as close as possible to our budget would be appreciated.
Thanks!