+1 on the fitting. It doesn't have to be a complete, cover all aspects of the bike and you fitting, as those are expensive but you need a solid idea of what size bike you need.

Used bikes have that "bang for the buck" feature that's hard to beat but used bikes are not always around, especially when you want one. I'd still spend some time looking used.

Talk to your LBS (dealers) about left-over models as they're the best deal, usually, on new bikes.

At the risk of raising the torch bearing mob I'd mention online sellers as well. Prices can be quite good. I'd just add the caveat that if you're new have the final assembly done at a LBS. Some shops get their noses out of joint with online bikes but if they refuse to make some money (50-75 bucks?) for a job that is labor only and introduces them to a customer who is open to the idea of accessories then it's not a shop you want to deal with for anything.