I've been watching for deals on a new copy of this for a while, and Amazon previous had it listed for $29.99. So for anyone looking to try this game out (even though it's reviews have been iffy), I thought I'd pass the word along.
http://www.amazon.com/Sega-10086690019-Sonic-the-Hedgehog/dp/B000G0HJ3K/ref=pd_rhf_p_t_2
http://www.amazon.com/Sega-10086690019-Sonic-the-Hedgehog/dp/B000G0HJ3K/ref=pd_rhf_p_t_2