Sector 201: 1500.00
Sector 202: 1500.00
Sector 204: 1800.00
Sector 205: 2000.00 — 2500.00
Sector 212: 2500.00
Sector 214: 1500.00
Sector 401: 800.00
Sector 404: 1000.00
Sector 416: 800.00
And last but not least, entry ticket (mosh pit): 1000.00

Remember that 1€ = 36 roubles

Click one, then you’ll be presented with the seat breakdown. Blue spots mark available seats, click on ones you want (though I can’t say which sector # means what part of the hall) and then hit the orange button below. The resulting orange form has several fields you need to fill in, top to bottom:
name
email
password
confirm password

phone
city drop down list (ignore, it defaults to St. Petersburg)
gender selection (why would they need that?)

The small orange button below submits that. I didn’t get past that (don’t want to book seats thus taking them from someone else) but I suppose it takes you to the payment form where you need to supply your credit card data.

Hope this helps.