I have been checking out some of the more sophisticated skins in the DNN store, the ones which have mega menus and sliders.. etc. While some skins show online demos of the skins, they have absolutely nothing on how to configure a mega menu or slider. On other sites like themeforest these add-ons, specially the ones which work with CMSs like WordPress, Drupal and Joomla, have their own sophisticated admin sections where a non technical person can configure the add-on without knowing HTML, CSS and Javascript. However on the DNN store I have no idea if the skin has a similar admin section so I don't know if the user is dealing with a jQuery plugin add-on where a user sets everything in JS or if there's a nice attractive easy to use admin section. You can ask the author and if they tell you there's an admin section, there's still no way if it's a simple non exhaustive one done in a hurry or an actually a good one. If they can't provide a demo for the admin section, I would then ask for a screen capture. 

The problem with skins is that there are no trial versions like modules. You download and test a skin and see if it meets your needs. That's why it's necessary for the skin developer to put up a full blown online demo.