Asset - Service What Type of Assets do People Buy?

A question for those who've sold assets on the Marketplace. What type of asset are people more interested in buying? Things that solve programming problems like scripts and engines for particular parts of games, or: sprites, sounds, and music resources?
The former but I only sell the former so... May not be accurate!
Of the first category are they more like large engines to provide a gameplay framework, or scripts to solve very specific problems, but not really create specific gameplay?


GMC Elder
Mine are all really technical in nature and solve a specific set of problems so they are never the 'basis' of any game so to speak, I have one or two free or inexpensive game engines that do averagely but it's more likely due to the fact they are very simple.