I have a second degreaser if someone wants to trade another polycount item or two (or something else other than vintage items) for it.
I wouldn't value them all equally - the degreaser, the Your Eternal Reward, the battalion's backup, and the gloves of running urgently are probably the most useful, and thus, to me, the most valuable of the polycount weapons. Most of the others seem average from what I've seen (mind you, I don't have all of them and thus have only seen them used by other people), except the shortstop and l'etranger (both of which I have) seem mostly useless, and darwin's danger shield just deprives you of your SMG or jarate for a small amount of HP. Some people seem to think the vita-saw is terrible, but it's actually great when you're using it to not lose your entire ubercharge when you die. It wins out over the ubersaw for me: If you are using the saw to attack, that generally meant you lacked a healing target and were going to die very soon, making the ubersaw's ability rarely useful.
That said, it looks to me like they are a lot more valuable than the non-polycount weapons at present, mainly due to their rarity. (I'm including the vita-saw in that category since it is craftable the same way, and apparently came out in the same update, even though it isn't part of an item set)