Offer can be published only when pricing plan is set up

Vendors can create a custom form, for Customers to fill it out during the checkout. Vendors are allowed to publish only those offers that have a pricing plan set up. 

Note! This doesn't apply to offers with "Use advanced pricing plan".

When selecting the "Publish" button without a pricing plan, a pop-up warning appears:

When don't have permissions to edit plan: 

When have permissions to edit plan: 

a. Close - will close the pop-up message.

b. Edit plan - will open Form page.
After creating an offer with checked "Use advanced pricing plan", but without pricing plans, the Vendor can't publish the offer and the customer can't see the offer.
When Vendor creates the first pricing plan, the start date should be prefilled with today. It is impossible to create the first pricing plan for future dates.

It is impossible to remove the pricing plan if it's effective from today.