However, I got feedback from keyboardists who have absolutely no problem with this price as long as the app does what they really need when doing their job. Maybe there are many other people who would buy the app, if it was cheaper. But including that market would make professional users unhappy by the time since the further development of the app would have to take the feedback of all those people into account - and could not focus on what professionals need. The needs of keyboardists playing musicals or other live gigs are different to those playing keyboard at home. E.g. I will soon support multiple input keyboards and more complex controller routings.
Btw., the lite version runs forever as long as it is in the foreground. Only the background time is limited to 30 minutes. Select "Never turn off display" and you can use the app the full day and night in your studio.
All those alternatives you mentioned would be more expensive than this app, at least if one already have an iPad. Or they would require lots of time of configuration. Master keyboards with that kind of functions are very expensive - however, with this app you can buy a cheap one, or one which focuses more on great hammer action than complex midi functions.
Apps like AniMoog and iMS-20 are from big companies which use their apps to just be presented in the app store. Lots of the knowledge which was necessary for developing these synths was already in the company and only had to be ported to the iOS system. Don't expect that synths like these would pay of for that price; you really have to see it in the company's context.
However, I know that some customers don't care about that and feel uneasy to pay so much for an app. But I hope that I find the users who see this as a niche solution for their exact problem.