So I was looking at someone's deactivated inventory, and I saw the Red Submarine. There were a few on the market. I go look at it now, and they are not there, but the item still has them in circulation. Is this a bug? And where can I find them on the market? And does this happen with other items?

http://forum.toribash.com/tori_marke...=red+submarine

They're still there, I think it's just your errors here.
Also, circulation only means that they've recently been traded/changed hands and not that they're listed on the market. (iirc)

It might be because of your TC not being high enough (if you're searching with X amount of TC)