No substantive trade value.
First, he's injured, recovering from a foot problem. Nobody gives much for a questionable health player.
Secondly, low value players like Pass are almost always FREE. When they get cut, any team can sign them. It's not like a team that lost their starting RB would want or need Pass to fill the slot. He has had value to the Pats because the Pats more than any other org value flexibility as an attribute. Most teams are not of that religion.
We just saw the Pats trade an OL with specific strong skills to fill a slot on a team which just lost their starting center. The trade was conditional and not for a high draft pick.