Just thinking out loud here but what do you think about just selling the ones you already have, to say, oh, I don't know, maybe me. Now, I understand that this may sound counterproductive but, when you really think about it, it's a very good idea -- (of course you may need to be inside my head to grasp the full affect of how good of an idea it is) but, hear me out. If you sell them, then you can take the money you make off of them and start a new collection using more readily available chips -- nothing comes to mind right now, but I'm pretty sure you'll be able to find something. See here's the problem with looking for "Empress Joliet's", and trust me, I live this everyday when I go to look for more chips for my collection, those of us with these chips, kind of like to hoard them. They basically become members of the family who eat way less than our children so at times we love them more -- okay, truth be told we love them more than our kids all of time.
So, anyway, like I said, I was just thinking out loud and thought I'd roll that by you just in case it sounded as good to you as it does to me.