Well worth thinking about chris. I have sold a fair few (100's of thousands) sets of christmas lights in my time...
Look for sets that have
more than a one year warranty. Obviously you buy before christmas hence your warranty does not cover when you get them out next year.
Alot of the chinese import lines are designed to fail within a year, even for the globes to fade within the month of sun. No one will ever admit that, but IMHO they do use parts which are not adequate to last.
Buy from someone like bunnings that will happily warranty them...
I have been swapping the same 800 piece set for 5 years now no problems... Everytime they fail I take them back...
It is surprising how much money one spends on lights thoughtout their life time.. I am merely 26 and can honestly say I have spent over $2000 on various sets etc... Although I am a bit of a light freak... Hence my screen name.