Most scrapbook stores and even the larger arts and crafts stores have at least some of their scrapbook items on sale or discounted in a special section. These items may be out of season, an item in limited supply, or just something that didn't sell well at full price. Just make sure that you check the item over to make sure it is not damaged or missing pieces. Sometimes the reason an item is in clearance is because one part is missing. If you can use the pieces remaining, then go ahead and purchase the item, but be sure to check it over.
This is also a great place to find older idea books, technique manuals, software, and magazines from previous months. I have found that some of the stores discount these items by half price or more. Another thing to look for is when the next big sale will be or look for grab bags.
At the Creating Keepsakes Convention in Houston last month there were multiple vendors offering bargains. Some offered discounted items, some offered grab bags, some offered multiple purchase discounts. The important thing is to look for the bargains. Be flexible and think outside the box on how you might use items that are one sale.