Right now from 1248 ₽ per hour for one GPU. The final price depends on the server and the disk, and is shown before launch.
How is it billed?
By the minute from your balance, from the launch including the image download. If the server does not start, nothing is charged. Top up with a Russian bank card or via SBP. A stopped server only pays for its disk.
Can I stop a server?
Yes, stop it from the console when you do not need it. The disk is kept and billed separately at the rate shown on the server card.