Without knowing anything about your playing style, it's difficult to say. Overaggressive picking or strumming could certainly lead to premature high E string failure, as could repeatedly bending beyond a full step. I use Ernie Ball .09s as well and know them to be dependable.

Anyways, you might consider purchasing multi-packs of identical unwound strings (usually a 6 pack) for less than $1.50/string. That would be a lot less expensive, and less labor intensive than purchasing and replacing a whole set of strings every time you break one.

Sascha