It's been years since I've seen a price difference for airfare on a reputable, major OTA.

It's used OTAs in a few cases:
- the airline won't accept US credit cards (or maybe my bank won't let me buy from them?)
- I'm redeeming Chase or Citi points
- I've traveling for a client who wants everything to run through their OTA for expedited expense processing (or, just to minimize red tape associated with *not* doing so).

It would take a pretty big discount for me to turn over my credit card to a sketchy OTA that I don't know much about. I'd worry less about the original charge (knowing my credit card would probably have my back) and more about the trip getting screwed up as I'm about to travel or during the trip.