Upload & Sell: On
The 50 macro is one good lens, and if you factor in its age, size and price, it is a superb lens. Psych's clock picture shows nicely its application scope.....not just for macro photography. Perhaps some day Canon will update it (and double the price, as that usually goes).
However, there is also very excellent EF-S 60 f/2.8 Macro.....that is also one of those lenses I wish I hadn't sold.