sylvius wrote:
Buy a used bike on Craigslist. If you search obsessively and jump on a deal when it comes up you can pretty regularly get bikes that are a year or two old in good condition for 50%+ off new prices. Only potential snags are if you need an odd size or live in a rural area. Otherwise I see 54-56 cm tri bikes popping up pretty regularly.
If you want the comfort of mind of buying from a dealer, look at pros closet or mybikeshop. Prices are often not as low as craigslist but still considerably less than new. To my mind the only real benefit to buying a new bike is getting it from an LBS than can help you fit it, service it, etc. If you are looking to buy online anyway, I'd definitely look used.
I gotta say - I used to think going used was always the way to go, but I don't think it's such a good idea anymore unless you're comfortable wrenching your bike.
I got my bikes new, but after several years of solid use, various parts got worn, fused, etc. I had washed the bike exterior and replaced the chain regularly so both bikes 'looked' new, but lots of badness had happened - headset couldn't be removed (fused), headset bearings shot, pedals frozen on, ferrules stuck into the cable guides, etc. These are little yet seriously annoying things that will give you a big headache down the road if you're not ready for them.
If you're comfortable pretty much disassembling your bike top to bottom and putting it together back up, used bikes are great as you'll quickly see the big problem spots and negotiate down the price if needed.
My LBS charged me $100 (and I think it was legitimately earned) for spending over an hour to unfuse my seatpost and headset. Fortunately, I had done the rest of the problem work, and it wasn't easy so I saved a bunch of money that way (but spent it all in replacement parts and then some.)