If I'm a rival GM, I'm looking at Khokhlachev as a guy that simply hasn't been able to make it as an NHL regular during his rookie contract, despite there being jobs to win on the Bruins. Yeah, it's possible that Julien and Sweeney are just ignoring his talents, refusing to give him a proper chance, and/or misusing him when given playing time. It's also possible that he may be nothing more than a AAAA player that is useless defensively. As a rival GM, I'm not willing to risk a higher round draft pick on such a player, especially if there's a decent chance I can get him for nothing more than the vet minimum once he becomes an RFA after this season. And, even if I miss on being able to sign him, there'll be plenty of other Khokhlachev's available.
So, yes, his trade value cannot get much lower right now.