I should let a friends game when only one have purchased the basic game or extensions
My suggestion is a good comercial idea that I'm sure would improve the success of Catan Universe.
Why this politics so protectionist? It limits the atraction of this game, when there are other very good and more avalaible. For exemple, very often, when I can't play with three friends (very very often) we go to Risk, were we don't find these limitations. If one have purchased the basic game, he can create all the games we wants with his friends (6 players) even if nobody else has purchased it. It's why Risk its becoming more and more popular each day.
Please, open the availability, for the basic game and for the extensions. This is the quicker and less expensive way to promote the game.
For exemple, I could invite 3 friends and introduce them to the game. Another day, other different friends and so on. I can be the only one to have purchased the game o the extensions we play. These friends, learning a new and very interesting game, would like to play and invite other friends (I am nos the only one and I would not be ever avalable to play with them. So, they would purchase the game or the extension they love, and go on propagating the game with other friends, etc. This is a multiplicative way to expand.
Here is my free, and I think very forthwhile tip for you, because I love this game (but can't play to it with my friends most of the time).
If you think, your friends shouldn't pay for the game (development, programming, servers, hosting, maintenance, updates, customer service, ...) you may buy the physical board game (on your own costs).
So every day you can invite some friends and have fun with the game and your friends and they don't need to pay anything.
In my opinion the online version has several advantages, for example that one can play over distances without travelling, all players can meet online for a game with much less time for a game, and so on.
If you compare the price between the physical board game an the online version in Catan Universe, the online version is a bargain - even the board game bunde (basic game + seafarer extension + cities & knights) is cheaper than just the physical base board game.
If you want to play Risk, then just do it, but if you want to play Catan, stop complaining and crying because of low prices - expecially when you don't need to pay for others but everyone pays for himself!
I think, Catan it's worth it!
You should just charge more for the game and let others play free. Is not easy to make everyone pay.
I prefer the current system - inexpensive for everyone rather than expensive for one person and free for others. Each game or expansion in the app is only about $5 US (plus tax and host fees) vs about $50-$60 US for the physical base game or major expansion.
Plus with the app you can play with a much larger pool of people, or play single player, or play just two people with bots - whenever you want, unlimited. You don't have to wait on the availability of the one person who owns the game.
If you like the game and want to play, you should be willing to fork over a few bucks. And you can even reduce the cost by getting gold in bulk and buying game bundles.
I believe want your thinking of is a Pass and Play and that hasn't come out yet.