https://www.cnet.com/news/youtube-tv-vs-sling-tv-which-live-tv-streaming-service-is-best-for-you/

There are two glaring differences between the two services, and they're directly related to each other: cost and number of channels. 

Sling offers three different tiers of service: Blue (usually $25), Orange ($25) and Orange & Blue ($40) with a mix of channels available. Signing up for the basic Sling TV is cheap, but you could quickly find that the costs pile up once you start adding channels or features. It costs an extra $5 a month for a DVR, for example, or $5 to add packages such as Comedy, Sports and Kids, which include extra channels such as TV Land, NBA TV and Disney Junior, respectively.