I don't travel unless it is discounted. I've used Priceline, Travelocity, Travelworm, or a name-your-rate hotel site. They all work pretty well and the only bad experience I had was when the reservation was made for me -block of rooms at a wedding- but that wasn't the travel site's fault. It was just a run-down hotel with apathetic staff.
Pricing is going to be a bit higher than the big number you see when you're browsing. There are additional fees that aren't reflected in the ticket price, but you'd pay for those anyway regardless of where you bought your ticket. It pays to be flexible on departure times and days. Fly out on a Friday eve, you're gonna pay more for it. Even 12 hours difference can save 30-50% on tickets. The wife and I found an air-fare deal for our niece to come for a visit ~$400 round trip. Her folks weren't comfortable with what we'd found and wanted specific departure times and dates so they could be there to help her get to the gate (long BS story) and chose a flight departing 6 hours before the one we'd found and returning 12 hours earlier. They paid around $700.
One important thing: The discount airfare sites can detect in your cache that you've been browsing the same flight more than a few times. The rates may go up tomorrow as they "know" you're becoming serious about taking that flight. Sneaky buggers! Clear the caches or browse with a different PC/IP.