Opinion On A Potential Anastasius

Actually Zeno is the last emperor to be in the "Roman" category of coins. Anastasius is the first when it comes to Byzantine.

As for the coin, the obverse looks decent and if the reverse is in a similar condition (the two pics in the description aren't loading completely for some reason on my computer so I can't really see the reverse), then it might be an ok buy for $9, not a great buy, but ok.

For Anastasius and the price, go for it. But don't get hung up on the bidding if it goes much higher.

The reason coin collectors consider Anastasius the breaking point between Roman and Byzantine is that he did the currency reform that introduced the large M reverse standard 'Byzantine' coins. If you want a coin of the last Roman in this sense, you need a pre-reform Anastasius which would be an AE4. For comparison, here is a 40 nummi coin like you propose and and a 1 nummus from the first part of the reign when Anastasius might still be called the last Roman emperor. It is a very artificial distinction so you can collect whatever you desire and call it whichever you wish and make a case for the coin representing the switch-over.