I've been struggling with trying to set up e-commerce while still using caching to maintain performance. Of course, the issues are that caching and e-commerce plugins don't always play nice together.
I noticed that Shopp has a "Cache Helper" plugin designed to help it work with another caching plugin. But they say it can work with plugins like WP Super Cache if you do these things:
1) Tell your caching plugin to not serve cached pages when the cookie is detected (default cookie is 'shopp_items_in_cart').
2) Tell your caching plugin to never cache the pages listed in the 'No-cache paths' setting of this plugin.
3) Make sure your caching plugin honours the 'DONOTCACHEPAGE' constant. Currently W3 Total Cache and WP Super Cache are known to honour this constant.
#2 and #3 are easy. How can I achieve #1 with WP Super Cache (if it's possible)?