The thing with collectibles is that you can't set a fixed price on any of it, whether you're talking about razors or baseball cards or stamps. I know there's pricing guides out there for most collectibles, but those are based on recent average prices, not an any intrinsic value.
As a shaver, as several people have pointed out, that blade wasn't worth more than a tiny fraction of what it went for, and NO razor is worth more than a few hundred dollars at the very most.
However, there could be two guys out there trying to build a collection of a particular era or style of razor, and both needed that one razor to complete their collection.
In a case like that, the only limit on the selling price, is the depth of the wallets involved.