I got a half real cob coin from around 1715, Philip V, for around $40. How much do you think it's worth? It's pretty cool, so I don't mind. The other side says Phili and has 1/2 and not much else.
A cob is not a denomination, but a way of striking a coin. So what you may have is a half Real. What is the weight? If it's about 26 grams it is a full 8 Reales, 13 grams a 4 Reales, 6.5 grams a two Reales, 3.3 a one real and 1.6 grams a 1/2 real. There are countless replica coins out there so you need to confirm it's silver and them weigh the coin. I have not seen a cob with a 1/2 on it.
I'll try to take a picture of it. It seems like it is a half real. The 1/2 is hard to see, but it's there. The Phili might be part of another word that didn't fit on the cob.