Distributor: Specific Vendors Prices

1. Select Create new price button:

A pop-up window will appear on the right side. The 'From' and 'Till' dates are fully included in the selected period. The selected 'Till' date will represent the entire day.

You can edit prices for previously added price configurations, both added in UI or by importing. Press "Edit" and a pop-up window will appear on the right side.  Vendor field will be read-only, you can change the Time period from-till the prices are effective and adjust the markup. Press "Save":

2. For importing prices, read this article:  Import prices.

3. The price tier can be deleted, but a deleted price tier cannot be assigned to new or existing sellers. Sellers from the deleted price tier will be moved to the default price tier, which cannot be removed. The distributor can create a new price tier with the same name as the deleted one.
If you will select "Delete" the following message will pop up: