I'm not sure if it expires or not, I've had some stuff just get clumpy and gross on me. I find that after a long time of using the same stuff, it stops working as well for me. I usually try to have two different kinds of shampoo and conditioner and switch back and forth... but I'm weird.
Some days I need a deep condition, some days I need a dandruff shampoo. Meh. It works for me.
If you've had something that came from Price Club I think it's probably time to upgrade.