The $1,200 item is an optical tube assembly.
The $1,700 item is an optical tube assembly, a mount, and a tripod.
The picture in the $1,200 listing showing the optical tube mounted w/ tripod is not correct. The picture shows a complete breakfast, the fine print says * part of a complete breakfast
, but the thing you're actually buying is just the cereal. What you really want is the cereal, milk, the apple, bacon & eggs. Especially the bacon.
And if I'm perfectly honest, it's a damn good thing they didn't ship it to you. $1,200 + $330 shipping for an 8" SCT OTA is a ripoff.