Here is something I found interesting as far as rarity goes. Why are there currently 4 listings for CIBs of Espial, but no loose carts.
search : tigervision 2600
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2047675.m570.l1312&_nkw=tigervision+2600&_sacat=0