If you already know what you're looking for, this is the best place to go for any number of supplies. The selection of paper, pens, paints, and anything else you're likely to need for your creative needs are here. Prices range greatly as they stock a large range of products from very cheep kiddie quality to shockingly expensive and a number of levels inbetween.
The store does take a bit of getting used to as the layout isn't necessarily logical and the employees can be best described as oxygen thieves. You're usually better off asking a fellow customer and hope that they just happen to know what you're looking for.