Why gamble? It's actually one of the easier ways to acquire high-level pieces in game, if you have the gold to spare for it. Since you are guaranteed at least a Magic-quality item, and a 1 in 10 chance of a Rare, it's actually not a bad early way to equip low-level characters. At higher levels, it can be easier to build a character specifically for farming gold and then using that gold to gamble up Set and Unique items. Because you can target the exact type of item you want to look for in Gambling, many players find the combination of a gold-finding character and Gambling a great way to find elusive items.