plan to go there,

please enlighten me of certain issue

1) ticket pricing
- is it in sgd or usd?
- when it stated two consecutive days for the combo tix, that mean 1 day for USS and another day for                    aquaria? as if i buy USS 2 days pass, i can enter USS for 2 days but if i buy combo, i can only go there for 1 day?
- prefer to have ultimate express pass, but stated it is starting from $30, what does it mean?

2)transportation
- can i just come from jb and directly going to USS, something like shuttle or something?
or i need to go to a place in sg before waiting a shuttle or bus, or cab, or anything?

3) accomodation
-previously thought wanna stay there, in sg, as i browsed through booking.com for my price range, all look 
to increase the budget doesn't seem worth it, jalan2...come back and sleep, don't wanna waste 1000 just for that
-it is recommended to stay in jb, and taking transportation to sg? 

thank you