Firstly: I’m a software developer and I work in web development. Secondly: I hope I’ll not be misunderstand, I’m suggesting these to increase the usefulness of the site. There’re many time-consuming things which can easily be done in the scripting side:
1. Thumbnails: You can let the user crop images in different sizes as you wish. It’s not a big issue and I believe the developers of audiojungle can easily apply it. (see: imagemagick)
2. Creating an mp3 version with ffmpeg is possible. So the user can uplad a .wav file and the system can convert it into .mp3 or whatever.3. Also, as far as I know, creating a watermark audio is possible with ffmpeg, as told here: http://stackoverflow.com/questions/14498539/how-to-overlay-two-audio-files-using-ffmpeg
4. Creating a zip file for end user is also possible in the scripting side. So you can let the user select what to send and the rest can be done by the script.
So the user can only upload thumb and .wav files and the rest are prepared by the software. It works this way in cdbaby and bandcamp.