can anyone recommend a ecommerce package

I need an ecommerce platform for my site - choices seem to be though

The easy ones to use cost low dollars but have very limited functionality

The "opensource" ones require you to have linux and PHP knowledge (and pretend that "well, everyone should know that shouldnt they")

The good ones that are easy to customise and use cost more than the store will make in a month . . and then hook you 5% charges

Any ideas?