Actually you might not even need to buy Pythonista 10 times. A single Apple ID can be used on up to 5 devices (I think), so you could use one Apple ID per group of 5 devices. I think there are also ways to purchase volume licenses for iOS apps, but I don't know what the requirements or the prices are for that.
Welcome!
This is the community forum for my apps Pythonista and Editorial.
For individual support questions, you can also send an email. If you have a very short question or just want to say hello — I'm @olemoritz on Twitter.