Okay, cheapest air fare you could find: KL - MIRI
Flight: Air asia
Price: 179.99 RM (pp)
Best thing to do when heading to KL is to either take
a) Bus
b) Train
Bus is the better option; it's faster.
EDIT: My dad tells me there's a cheaper flight available if we take Johor Bahru - Miri
Check this site for more details: http://www.airasia.com/skylights/cgi-bin/skylights.cgi
Other than that, nothing more to add. Wait for updates.
PS: Big thanks to Dad who helped me out a BIG DEAL here.