Yes..... you did lose the auction but not necessarily by fifty-cents. For all you know, the guy/gal who did win the item, placed a bid that was $50.00 higher than your top bid but thanks to the way the e-Bay bidding process works, the bid "increment" was at the fifty-cent level. Realistically, you don't know if another buck more would have won the item for you.
The only time I ever get upset over losing an auction is when I enter an amount that is less than what I would have paid for an item and then it's my own butt that I kick. In the final analysis, the value of an item is what one person will pay on any given day. The next day, the same item could be worth much less or much more. That's the way it is.