Purchase cut off is a setting that prohibits purchase options such as Make Offer and Buy Now for lots. Once the auction reaches the cut off time (e.g. 48 hours before the auction end date/time), users will only be able to bid on items and can no longer make offers or buy now (depending on your auction settings).
Purchase cut off does not apply to Listings. Listings will display purchase options until the item closes.
To set or edit the purchase cut off:
Navigate to your auction
Go to the General Settings tab
Click the Puchase Cut Off tab
Select the desired cut off
Click Save Auction
The cut off time indicates how long before the auction end date/time the purchase options will be prohibited.