For a bulk buy to use Farmer's Cellar order forms the coordinator simply needs to:
1) Create a Google order form and add all the available products and prices, like normal
2) At the bottom of the form edit page, check "Allow responders to edit responses after submitting"
3) Share out (with edit privileges) both the form and the associated spreadsheet to firstname.lastname@example.org
To see a quick how-to instructional of these steps, watch the video below