Good deal for four bucks. I just bought a similar 1826 1/2 Mexican Republic reale off ebay for the same price tag.
Actually it has a melt value of basically $1 and usually no dated culls sell within this price range.With a date and decent detail I would value this around $10 mabey a little more.
For me the history of coins is what is attractive to me. I love beautiful coins and I have some, but pondering where and when a coins journey took it is the most attractive part of this hobby for me. The wonderful part of this hobby is that there’s so many angles to approach it from. Nice coin!