Prime members only. Ends 9/30. Amazon is offering 3 months of Starz for $5.97 ($1.99 per month) via Prime Video Channels.
It's $8.99/month after the 3-month promotion (cancel anytime). Prime No-Rush shipping credits can be used to pay for service as well.
In addition, Starz has a similar offer: 10-months for $20 (new subscribers).