Juggling players and their personalities can be harrowing at times, especially when some of the players aren’t exactly friendly towards one another. It doesn’t help that some players tend to steal the show once in a while and re-railing them sometimes makes the game concentrate on their character more than others. As a GM, you don’t just manage the game setting, environment and NPCs, you also have to sometimes manage the people playing the game as well.
Give players an inch, and they will take 1.9174×1013 miles. Fortunately, as a GM, you have clairvoyance and can grant misguided shopping spree wishes when you know that there is no chance they will ever benefit from their ridiculous requests.