After wondering for a long time when these 7-Eleven cups came out and how many there were in the "set" (I didn't know that there were two sets), I luckily chanced upon Mark K. Larson's Complete Guide to Baseball Memorabilia, Krause Publications, 1996. In this book (pages 458-460), I found complete listings for these undated sets.

Believe me: I couldn't have pieced this information together without him, even though I had accumulated quite a few of the cups. It's nice to know how many there are out there that you just have to have! What follows is an excerpt from a book Mark and I are planning to do on sports drinkware, so if it doesn't sound like me, it's because it's going to go in our book. I'm pretty sure the information is accurate. I'm not too sure about values. I do know that these cups are getting difficult to find, especially in nice condition. The big name players cost more everywhere you go. Flea market vendors aren't totally stupid. Condition is all. Pay for what you want to end up with. I've always thought that these cups were pretty neat. The complete sets are certainly challenging, but my feeling is that they can with enough perseverence and currency be completed.

If you finish the sets, you'll have something not many other collectors have--if that's important to you. I collect these things for my son who some day may find them interesting; I don't expect to make any money on them. I also don't expect to pay more than $5 to $10 for any of these cups, though Larson prices some of them at $50 or more. If you like 70s vintage stuff, baseball, and plastic, these cups might be just the thing for you!