You are right -- typically courses in the $X k range need some interactive component -- but it needn't be a webinar.

You want 2k+? -- offer to edit 3 emails -- you probably wouldn't get enough takers to take too much time. Also, it price anchors the $249 and you can do it like Kickstarter and limit the # of sales of bonuses like this.

For $10k or more, write a first draft of emails and look over the final draft after they edit.