I'll second looking into an M13.
I have recently acquired one (Cheers ragnarock!) and it is lovely. I find myself using the MX518 a lot less, and as it sits on the shelf above my M13, that's good (I get mouse arm after a while, and the M13's trackpoint encourages me to keep my hands much nearer the KB for much longer).
Bear in mind though, that mine was virtually new, and a lot of M13's out there will have seen some heavy use.
IIRC, ironcoder is not in indonesia, though I am not sure if he wants his location published. I'm sure he will say if he doesn't mind.