We work in a RTB (real-time bidding) system, therefore prices will constantly change. You need to log in to your account and choose Campaigns > Create new campaign in the admin panel. There you can see the highest bid prices based on your targeting preferences.
You can see the required minimum bids for certain targeting options on the Advertisers > Pricing menu.
If you are not sure what to do, just hit up your account manager and we will help you optimize your campaign to get the best traffic on the best price possible in our network.