I have a simple question. I consider buying 0.45. If later there is a 0.50 for an example, do I have to pay another 10$ (€ in my case) to play 0.50?
At the top it says "you own this game" and a download button. If you buy it at 10$, future updates that are also 10$ you can download. At least works for me.
You won't have to pay again.