You do realize that internet over satellite is nothing new. Right?
People in Iran bought hotbird accounts for broadband connections more than 15 years ago.
Hotbird, Telstar, etc. have been offering free satellite channels in Iran since at least 20 years ago.
I don't really get what these operational costs that you talk about are. Whether they want to cover Iran or not, they still have to launch these satellites. And because these satellites are in LEO, they will eventually pass over Iran. So, it doesn't really need more infrastructure if the network has free bandwidth. They can dedicate a small bandwidth to Iranian subscribers, for example.
And whether they include Iran or not, the lifespan of their constellation is not going to change.
It's not like more people use the signal, the sooner the lifespan ends.
Honestly, 20 years is impressive for LEO. I don't think the lifespan of satellites in LEO exceeds 5-6 years. If 20 is true, it's impressive.
About ground stations, why do they need ground stations?
Your dish possibly has the sender and the receiver in itself.
I don't get why we still need ground stations. What do these ground stations do exactly?
As for the price, it's not that much for most subscribers. As I said, I am already paying about $10 on average, some months even more. I would happily pay around $15 to $20 for such a connection.
The main issue is how Iranians are supposed to transfer money to Starlink. Not the cost itself. Maybe only cryptocurrencies like USDT can enable Iranians to do this.