If you tag a player you better have an intention of paying him, because if you can't get a trade then you're on the hook. Huff would have been $21-24M depending on whether he's considered an end or a linebacker.
Oh no! We couldn't go paying him when we have all these elite offensive linemen to pay...
Also, there's no way we couldn't trade him. He clearly had a market. Even if you take lower draft compensation, you're getting more than nothing.