You are on the right track with King George. Britannia looks a little more spiffy today, but her depiction on your coin indicates British origins for sure. The Spanish were the colonizers of Colombia, so early Colombian coinage shows King Charles and other such monarchs.
You have a genuine item or a replica of an old British Columbia farthing token. The people over at AboutFarthings.com have helped us many times, and they did it again with your coin. There are smart people at AboutFarthings!
CoinQuest thanks AboutFarthings for use of their coin image. Please click on this link to their web site for plenty of information on Columbia farthing tokens.
As to value, the first question is real or fake. Value is always tricky business with tokens. The collector following is much smaller than that of legal tender coins, so the market is finicky and unpredictable. I happened to find this auction link that sold a piece similar to yours for only $10 US dollars. That sounds like a bargain to me. I would venture more like $50. Typical catalog values for genuine Columbia farthings run like this:
worn: $35 US dollars approximate catalog value
average circulated: $80
well preserved: $200
The design varies a bit: the portrait can face left or right, there can be a fasces under the bust or not, and the letters COLUMBIA can be above or below the bust. The reverse is mostly the seated Britannia, but some coins show a standing 'Justice' with sword and scales.
Remember that retail values are not what dealers pay for coins they buy. Dealers need a substantial mark-up to stay in business, so if your token sells for $50 retail, and dealer might buy it for $20 to $30.