Rare?  Doubtful.  Unique?  Possibly.  There are thousands & thousands of collectible casino ashtrays out there.  Yes, there are rare ones and there are unique ones, but the majority are the more common ones.  You might find these at local flea markets or yard sales.  If you live near the older, established casinos (such as in Las Vegas or Reno) your chances are better to find a tray that has more value.   

As a casino ashtray collector listing trays at auction, you should research the casino itself.  Was it located in Las Vegas or Reno?  Is it a card room in California or a riverboat in Indiana?  Did the casino open and close within a matter of years or is it still operational?  There are books galore and much information to be found on the internet regarding casinos.  Use this information and provide your prospective bidders with all the details you can muster.  You can never have too much information, but you can always have too little.

Don't assume that the size, shape or color makes an ashtray rare or unique.  Don't assume the tray is valuable because the casino was imploded after 40 years in operation.  If you look at other casino ashtray auctions on eBay and you find there are several others just like yours, then yours is NOT rare!  You may have a better auction if you group several trays in different styles together from the same casino. 

A close up photo with your detailed listing will generate bids more so than saying you have a "rare" casino ashtray.  Be certain to disclose any defects or damage.  Everyone knows the purpose of ashtrays so we all know there will be some fleabites on the rim or maybe some pinholes to the graphics.  But, if there are chips, cracks or rubbed-off areas on the graphics, please tell your bidders.  If the tray is not absolutely perfect, then don't say it is perfect.  We're grown ups; we can take it.  Keep it simple, but definitely keep it honest.

The auction has ended and it is time to ship the tray.  Wrap the tray in paper and then in bubble wrap before putting it into a box.  Do NOT ship a glass tray in a padded envelope... you can get free boxes through eBay or from the post office, so please use a box.  If you are shipping more than one tray, wrap them individually and then tape them together.  The best way to prevent breakage is to wrap and pack tightly so there is no movement as it is the movement of items that allow them to break.

Send a note to your buyer letting them know the package has been mailed.  Tell them you will appreciate receiving positive feedback from them when the package arrives and immediately leave feedback for them.  Get your next batch of photos done and list more items for auction and have fun!