Nowadays, anything 10,000 and above are just multiples of 萬 in Mandarin and Yue, e.g. 十萬, 百萬, etc. Malaysians (of any dialect, not just Min) tend to use the Western convention of multiples of 1,000, e.g. 十千, 百千 (admittedly, I cringe whenever I hear it - even though I find myself using it just to comply with the majority!). The most likely reason is psychological congruence to the Western mathematical conventions forming the basis of our education - a fair approach from a practical standpoint, though it has killed off two very nice words!
As an aside from Chinese linguistics: I picked up a couple of really cheap books on the Chinese abacus a year back. Did you know that with some practice, it is actually possible to calculate square, cube and... get read for this... 5th roots!! using an abacus?? The formula for them is actually lower secondary stuff, but to actually use it at high speed is the true mental marvel... or monstrosity, if you will.