dami pera pre ah.
i have a mountain bike too pre, my personal opinion sana is for you to just increase your budget a little bit. baka marupok na unit makuha mo, gagastos ka lang kakapagawa.

i also suggest that you assemble everything from scratch para maayos makuha mong parts.

pero tama si kimpoy. kung kukuha ka ng parts (o even yung assembled na), madaming maayos and maganda sa cartimar.

consider getting shimano parts on:

a) pedals
b) front fork
c) main pedal bearing.
d) caliper brakes

yan ang mabibilis masira sa taiwan made bikes. the rest, like yung frame, pwede ng steel dyan, wheels and rims, pwede na yung taiwan made, chain and yung derailleur, pwede na ring taiwan made.