In your Listings - in the Edit Listing journey, on the Set Rights page - you will see a setting to make your lising "FAST Enabled"
By accepting this, your listing will be available for FAST bundle deals in the Vuulr marketplace, potentially with other sellers. This increases the chance of a sale. It places an eye-catching orange 'FAST-enabled' banner on your listing in the Buyers' view.
Note that (FAST) bundle offers can only be accepted or rejected (because of the complexity of a multi-seller deal); you cannot counter-offer on any offered terms.
However, if you think there’s a chance of a negotiated deal, you can always propose that the Buyer unbundles your titles from the bundle, and sends a new separate Offer.