Definitely Gallienus. That neckbeard is unmistakeable. I don't see an exact match on Wildwinds. Will search RPC EDIT: RPC doesn't have Gallienus.
Well, sure, but perhaps not as much as you'd like. It's condition and common reverse type will keep the price down but you might be able to get ~$5-20 for it. Don't be mislead by certain eBay sellers such as Ilya Zlobin (highrating_lowprice) who would list a coin like this at $200, marked down to $80, and who might take $20. Here's an example of such a listing... and for this coin $20 would be too much: https://www.ebay.com/itm/351397060197? Here's the full attribution of your coin: EGYPT, Alexandria. Gallienus, 253-260 CE Billon tetradrachm, Regnal Year 3 (255-256 CE) Obverse: [AKΠΛIOVΓAΛΛIHNOCEVEVC]; bust right Reverse: Eagle standing left, head right, wings open, wreath in beak; L-Γ Reference: Emmett 3730.3, R1
I do not have a match for that coin but this is the same year and basic type for the co-Augustus (and father) Valerian. My birdy Gallienus is from year 13. Price of such things is very much a matter of opinion. My specimens were $53 and $65 respectively but you would find others who would value them at a fraction or many times those numbers depending on whether they were buying or selling. There is no 'Red Book' for Ancients and every coin presents 'situations' (like the ragged edge of my Gallienus OR his exceptional neck beard - there are people here obsessed with neck beards) that affect the number of people who might accept the coin into their collection. Is yours worth $5-20? Probably, but those of us who collect such things would rather spend a bit more and get better surfaces on a common coin available in higher grade so we would not pay $5 for that one.
Not a bad coin but keep in mind the real fun of collecting is holding a piece of ancient history in your own hands, which far outstrips the monetary value.
