Considering the item options you can get start game, health pots really aren't a bad choice. Depending on what kind of lane you're going to play, champions often choice if they want a boots or bigger item first. If you go boots, you have that extra gold to spend. Why not spend it in a constructive and inexpensive way such as health pots?
Health pots are particularly effective for jungles. It gives that extra health boost they need in order to clear more camps before going back and buying.
The benefit is definitely worth the cost.