Simultaneous turn in a turn-based strategy game.

...

For SoD, the current plan is:
a paid subscription for a month/year.

How much will the subscription cost? It's very difficult to say right now.
in the range of 60 - 600 rubles per month
.....

Is the option being considered that, for example, an annual subscription would cost less if paid upfront, compared to the option of monthly payments?
I think many would save money with a discount - and your benefit would be receiving the entire amount at once, regardless of whether the person plays for the whole year or not.