I don’t think you can infer he is not interested in selling, just that he is not interested in providing a demo - perhaps he is worried about a demo being circumvented and is it worth that (a demo) for €45. But I know other companies do provide demos at that price point You of course have buyers’ choice of to buy or not to buy!
And we also do not know the developer’s personal circumstances that may influence his choices.
For example, I sell Java based librarians for about ten different types of keyboards/rack synths that I own and have done for about 20 years. I do not go out of my way to advertise them. Why not, when I could potentially reach more people and make more money? The simple answer is I’m unlikely to ever earn enough from them to pay the mortgage and put food on the table and keep me in my accustomed lifestyle, and I have a full time day Job that does that. So I am happy with the trickle of sales I get that offsets my development costs that I put aside for VST purchases, but I do not want to be so big that all of my spare time is taken up in support.
So maybe the developer for this Obie is in a not dissimilar position. He has sufficient sales with his selling model and that’s enough.
Just saying, and, as I said above, to buy or not to buy is your choice if you do not like his approach. I’d be happy to take a punt on this if I did not already have Obie emulations. So, it is of interest but the Obie gap is already filled in my studio by many Obie emulations .