Hi Sascha,
I agree with you that this has to be better communicated. And I’m going to improve this over next month or so. But the situation is now very much in flux, I’m taking over TotalFinder support/development again after 10 months break.
Please, let me give you some context:
- in June 2015 we announced https://blog.binaryage.com/el-capitan-update, and decreased prices to 50% discount.
- in March 2016 we handed our apps to Steve, because he was motivated to continue and he had some ideas how make this SIP disaster sustainable: https://blog.binaryage.com/meet-steve-the-new-lead. He disabled the discount.
About a week ago we decided to take over again because Steve ran out of steam and wants to focus on other projects. Life happens.
TotalFinder is kind of a special app in the sense that it usually needs major rewrites between OS releases (it hacks Finder.app!). Features are not “guaranteed” because it heavily depends on what Apple does with Finder. I hope my documentation has always been pretty clear about that. But luckily for customers I was able to maintain TotalFinder feature-set over last 6 years and never charged for an upgrade. btw. This has been on our licensing page mentioning the risks of buying since the beginning.
Anyways. There is still great value in TotalFinder for people running on older systems or willing to disable SIP (which is not a big risk for a technical person IMO). And there is still support cost for me which is the major problem for me. For example writing this post was 10+ minutes of my day 
So my current plan is:
- make it super clear about the status of this app
- after step 1, maybe increase the price to repel new customers (exactly the opposite of your idea)
- don’t open-source it, because I don’t see much positive outcome out of this step, chances are very very slim that anybody is going to continue in TF development in the open. Also open-sourcing the code-base would require non-trivial work and would potentially expose existing customers to a risk in case there was some unknown security issue. Anyways, If anybody wanted to try to develop it further they can contact me and I would be open for private collaboration.
Ok, hope this honestly explained our current situation. And btw. we offer refunds, so even if you become an existing customer and then realize it does not fit your original expectations there is a good chance we refund you your money.
Peace 