There are a few sites out there where you can find some good shopping deals. A good one to keep your eye on is chainlove.com
it's a one deal at a time type of site where they offer one item until it sells out and then they move on to the next.
The reason I suggest this now is, at the moment they are offering a basic bike computer for $15. Only 20 left!
Better yet, chainlove split to mountain and road so now you can find road (and often triathlon) specific deals at www.bonktown.com.
For running stuff (and camping and hiking and whatever other outdoors gear you're looking for) keep a close eye tuned to www.steepandcheap.com. There are a handful of other sites too run by the some group from backcountry.com that cater to snowboarders, and other such stuff. That stuff's way to cool for me though... :)