Do you require all-season tires?
I assume no since you have GSCs and KDWs now.
www.tirerack.com lists 113 tires in 205/55R16.
Luke who works for Tirerack and helps many of the Contour owners out sings the praises of the Bridgstone Potenza RE730 , which is $104 per tire. Add about $15 for any tire to get it shipped to your door and then mounted at a local shop. I love the 215/50R16 KDWs on my 2000 SVT, although loud on concrete. My previous car used 205/55R16 and I've been through several sets.
Original Goodyear GT+4 sucked.
Michelin XGT H4 all seasons sucked.
2 sets of Pirelli P7000 SS were great, and looked cool.
Final set of Yokohama AVS-i (Intermediates) were awesome. When used as summer only and racing, they lasted as long as the P7000 SS and are cheap. I love the AVS-i, but the treadwear isn't that great to offset the lower cost.
Tirerack lists the AVS-i at $74 each.
I would stay away from Goodyear 'performance' tires. Too mass market for me and not enough grip, especially for the money.
I would try the RE730's next, but don't know if it's too far over your $100 limit.