A S$15 solution preferred...

This kid's bike Isaiah has been using lately is at least seven years old. The multi-speed gear coupling has worn out, bent and could not feed the chain into the gears smoothly anymore. Should the bike be abandoned totally since it is already quite old and perhaps other parts might give way in the near future?

A new bike costs S$95 but a new set of gear coupling costs S$15 (for parts and labour). The latter was adopted and now, for S$15, the bike is back in proper working order again. Should the entire bike become unusable sooner than expected, at least the gear coupling could still be salvaged for future use.

Besides cost cutting measure such as this, knowing some DIY techniques on self-repair helps to save money, too.