This forum is not a great place to find out how much a razor you have is worth. There are many other venues for that. Come be part of the shaving discussions.
If you want to know if it was a fair trade we'd need to know what you traded for it. If you are looking to resell it then go check ebay and use the completed sales option to get an idea what they are currently selling for. If you want to sell it to me I'll give you $10.