Buying a transfer/24h pass ticket at night??

Hi,
My train will arrive at the main train station in Prague on sunday night around 21.45.
I need to buy a transfer or a day pass ticket for metro (Hlavni Nadrizi).
As far as I know, the ticket vending machine takes coins only which I don't think I will have enough coins for it. And the information center will be closed already.
Will there be anywhere else that I can buy a ticket? Any ticket counter or kiosk selling a ticket will open that late?
Thanks

Kiosks sell public transport tickets too - try the newsagent shops in the building.

http://www.dpp.cz/en/fares/

The transfer ticket (validity 75 min.) costs 26 CZK. 24h ticket costs 100 CZK.

If you want to exchange cash and do not want to be ripped-off, do not use the exchange service at Hlavni nadrazi or Wenceslas Square. This is a good exchange company http://exchange.cz/index2.php , the office is near OldTown Square. The second table is for cash exchange - buying 18,10 CZK/USD, 24,60 CZK/EUR. Nakup = buy, prodej = sell.

Enjoy your stay.

So, there would be some kiosks, or newsagent shops open on that time right?

Yup. It's the main station of a big city, so 21:45 is not that late really.