No, not really. At $500, that's what I'd call a fair deal, an expected and normal price for a P232SL. Could you have made a profit? Perhaps, but not much, if at all. But then again, as you said, sometimes buying different guns is fun, even at a slight loss, just for the experience.
What you may have missed is the chance to own a truely superlative, world class pistol. IMHO, one of the best designs for perfect ergonomics ever.