Ulta recently had a sale on liters of some of their highest quality shampoos and conditioners. Most were $15. We printed off coupons for $3.50 off in addition, and scooped up these two liters: AG Fast Food shampoo and Redken All Soft conditioner.
Needless to say, we love these products! They smell great and our hair has never been healthier.
These liters are still discounted online (and possibly in stores?). I recommend signing up for their rewards program. You quickly accumulate points that you can use towards cash off or discounted services, and you get generous coupons in the mail.