Congratulations on buying an adapter! it will open up a lot of possibilities for lenses Canon does not make, like the 200mm f/3.5 and f/4 Tele Tessar lenses, or the 180mm, 45mm f/2.8 Tessar, and 135mm Sonnar models which are really affordable,excellent lenses. Being able to use Yashica/Contax lenses bearing either the Zeiss or the Yashica brand is handy.
Occasionally, if you're shopping in places like pawn shops, it's possible to find high quality lenses in Y/C mount that are erroneously under-priced.
Canon s-slr bodies adapt really well to other lenses,and the price you payed for the lens with adapter is less than KEH is selling the lens alone for!