Live transcoding pricing calculations are simple things. There are 3 types of profiles are available.
SD profiles charge 12.5 USD
HD profiles charge 25 USD
UHD profiles charges 50 USD
For finding the difference between these 3 profiles, you simply check the mentioned URLs
You can choose these profiles based on your encoding Bitrate. The encoding video resolution does not matter to select the profiles.
Based on your source bitrate, you can choose a combination of the profiles. For example, if the source encoding of the stream is at 5 Mbps bitrate, then recommended profiles or stream qualities will be 4 Mbps (Bitrate > 3 Mbps, so HD), 2 Mbps, and 1 Mbps. In this scenario, you need 1*HD and 2*SD profiles.
1*HD = 25USD
2*SD = 12.5 USD + 12.5 USD = 25USD
So a total of 50 USD per month you need to pay. Also, note that 50k Video Transcoding & Recording Minutes charge 20 USD.