Brewmaster's Warehouse isn't too bad, that's where I bought mine. A little cheaper than the other homebrew suppliers, although yeah - you may be able to save a couple bucks on eBay.
Be careful when you're buying, some come with a plug, some come without one (fine if it's going to be hardwired or if you're comfortable adding a plug yourself). Some have a center inlet, some have the inlet on the side; may or may not matter, depending on your setup. Center-inlet ones tend (from what I have seen) to be marginally cheaper.