Only when I can't collect something ever again. Water Rongo in FFVI. In Final Fantasy V I'm tempted to try to beat those monsters in the two towers.

I had to tell a friend you have to avoid the battles and go for the boss. It took three tries before I learned *Spoiler* that you can only use magic on the boss in the magic tower.

I tossed 7500 gold and it 'returned.'