praying to all the gods that nothing happens. not a great strategy i know. RAID is probably the best way to go but 100 Eur for a disk in Serbia well not that great.
I once had a HDD failure, long time ago (it was 80GB drive :) ) and it was my fault. It was - a lot and i was carrying it with me in my front jacked pocked, got in and plugged it. condensation an electrics not doing so well together.
Good thing is that most probably the electronics died and not the disk is dead. It should not be that hard of a fix for people that do that as a job. try finding someone that is not charging 700 eur for something like that.