I was one of the first players to buy the chemical gun when it was first released. It has had a major nerf, to do with the clip size, speed and reload time. It has been disabled in events and also in certain areas such as bases and in some stores, e.g. the trade house. So many people have it, and if you also want to be someone who was to own a chemical gun, I suggest you start winning some events, sooner rather than later
).
What would be the point of hosting "auctions" for something that takes months of hard work? That is the point of events.