From the ride height and fender design, it's likely to have come from Yogyakarta.
Here's a Becak Yogya identification guide:
http://issuu.com/matatita/docs/becak
If you go several pages towards the front, there's another article on becak, including manufacturer contact and pricing.
The traditional-style like yours go for up to GBP150, and the modern more streamlined one with 5 speeds go for GBP120. GBP2.50 buys you custom fender paintjob.
A 2-year registration is 63p.
The latest number plates begin with YB. Yours, hmm... could be an older style? Can't help there, sorry!
"Satu Hati" appears to be the becak co-op name, this is #1 of the lot. And "Kiki" is likely to be the owner's name.
Can I post this thread to an Indonesian cycling forum? People from Yogyakarta should be able to help more.