you can use adblock killer for it. so people can't access to your website if they have adblock.
i am sure people will be volunteer to click on advertisements to support this website. you are right about that price. 30c is almost nothing. but imposing it without any warning is not cool at all.
your goal is to collect 20k rubles. i can understand this but that means you have an expectation from 1000 people every month. advertisement + adblock killer can make it easier for you.