Yeah, they ARE pretty pricey, because between
www.discounttiredirect.com and
www.tirerack.com , there are a grand total of
2 tires avalable in a 245/50-16. Not much selection = high price.
A 225/55-15 might be a better match height-wise, it's 24.74" in height, vs the 225/50-15 at 23.8". The 245/50-15 are 24.64" in height. Other altenatives might be a 215/60-15 at 24.74", or a 215/55-15 at 24.31". Again, tire choices will be pretty limited in any of those sizes...
Most of the performance tire dealers are only carrying 2 or 3 15" sizes anymore, compared to DOZENS of sizes in 16" & 17".
