This kind of thing drives me nuts, maybe a decent reg is worth more than 125$ to you but someone else might have a different value for it. A lot of people don't buy things from LP, so list price is something that some people still pay.
Do you walk around in regular life telling everyone they are overpaying or under valuing things? If you walked into my store and did that you'd be outside pretty quickly. Don't use the anonymousness of the internet to get away with socially unacceptable behavior. Let other people decide what a set of sling shot fins is worth on their own and don't troll around on people's threads telling the world they are over-charging. It isn't constructive or considerate, or even accurate in this case.
Just so you know, I'm pretty sure I know where these fins came from, and they were offered as one of three "grand prizes" along side a reg that was brand new. So in that context these were seen as equal to a reg.