Xperia X users paid 50€ for one year support with possibility to extend it in the future by buying it for another year. But after one year there was no option to extend this support for another year. They said they will support Xperia X for free.

"7. What happens to my Sailfish X software after one year of purchase, will it still work? This was mentioned when I purchased the original license.
The Sailfish X software package contains software updates and customer service as long as the device is supported."