My A/C pressure sensor blew the other day - which in turn caused the A/C control unit to burn out. New A/C pressure sensor - $230, new A/C control unit - $1700. Luckily my mechanic knew someone who fixes control units (normally for the engine) - and got it rebuilt for $500. Does this happen very often?

I'm up here in Canada - where we might use the A/C 4 months of the year - so it can't be from overuse (I have an '02).