Craigslist is hit or miss - you'll need to check out the board before purchasing to make sure there's no cracks or other damage. Having to pick up the gear sucks too if you don't have a car. Same goes for eBay, although shipping makes pickup easier. :P
Timing matter as much as location; buying in the offseason will get you much deeper discounts than during the season.
I've actually made two websites that do price comparisons weekly for the following online merchants:
* Backcountry (which also does dogfunk and steepandcheap)
* The House
I'm working on getting SierraSnowboard prices.
For men, check out Shop Snowboard Sales
For women, check out
Snowboards For Women
Hope these sites help people out!