If you must purchase something and just can’t wait for a sale, try www.retailmenot.com
Search for the store or brand name you are interested in and coupon codes will appear. Some work, some are expired. If you are given a coupon code (through junk mail, etc.) you can post it on the site to share with others.
OR
When all else fails, search for it on www.ebay.com or www.craigslist.org