When it comes to buying something, my philosophy is "If you're happy with what you got, and if you can afford what you spent, then I call that a WIN!".
No matter what it is, you can likely find it for cheaper somewhere else. Or if you wait long enough you might find a great deal. A person can research and scour the internet for months, search every store within a 100 mile radius, find the lowest price they can find, and the day after they make the purchase they might see the same item for sale at half the price they paid. But that's life. I say, if you're happy with your purchase then that's all that matters.
As far as overspending, everyone does that at some point in their life. But heck, the way I see it, there are a lot worse things a person can do than overspend on a good knife.
Of course, if you're talking about the knife as an investment and refering to any possible resale value, I wouldn't know about such things.