Will throw in a few coins as well: Current way of discovering what exactly in premium content is not optimal from UX perspective. I'd even say it's pretty bad, as it's not obvious where details are presented. Obviously I talk only for ones which have the premium content field filled out (I'd expect ones with missing fields to be slowly filled out over time as admin time permits).
Since data is already available to page renderer (otherwise it won't show the premium content icon), I'd suggest adding a hover tooltip (akin to one when you hover over the part link) that mirrors the information shown when you press buy or at the very least add a title attribute for use of native OS tooltip. For mobile-friendliness first one is better with a behavior to appear on touch.
This is pretty minor issue and definitely not a priority, but as someone who spent way too much time improving UX in various programs such minor problems tick me off, all thanks to profdeformation. :)