Nope, I've never outright snapped one, played it till it sounds dull as sh*te but never snapped.
I play in a metal band though so I'm predominantly B and E string based so I always need to replace them earlier than the others. It's so expensive having to replace A, D and G as well each time I re-string.
Might but a whole set and sell the top three on ebay? Someone might want them.