I have an '07 G6 GT w/sport package.  It includes traction and stability
control and 225/50 VR 18 Goodyear Eagle LS2 tires.  Although the tires
are labeled M&S, I'm suspicious of their  "all season" capability in
snow.  Unfortunately, there are only 3 tires available for this car  the
Goodyear, Bridgestone Potenza (also M&S), and Bridgestone Blizzak Winter
Tire.

I'm looking for a reasonably priced alternative to the tires. Would it
be possible to drop down to 225/55 17 tires which are half the price.  I
don't know what that would do to the handling (traction/stability
control).

Any ideas?