Right now, .40cal pistols are likely experiencing an all-time low in the market. Even with that said, if you took that for $340, that was a home run if the gun is in high condition.
If the pistol is seriously in NEW condition and actually appears ANIB unfired outside of the factory, you did even better.
.40cal pistols likely aren't going to rebound in the market soon, but if that gun is in "time capsule" condition, $340 is a pure steal and fantastic pick-up.
I don't mean to open up a side argument (and I say argument because it usually ends up that way, with all sides certain of their position...) but if I were in your shoes and that gun were in 100% condition, I would start shopping for another 4006 in any condition for low money, so that I'd have one to shoot. I wouldn't send a single round through a time capsule gun that has zero miles in 29 years on it's odometer. For similar money, you could find a decent one that could shoot to your heart's content.
MANY will disagree with me. I'm fine with that.