I booked a ticket through OneTravel and had a problem with the booking. The details aren't important. What's important is that I spent hours and hours on the phone with customer service. I talked to several supervisors: all in all, I was given a big run around and a lot of utterly wrong information. They are not a reputable company and if you have a problem you will not be able to resolve it. I am not quite sure if I'd call them a scam but from my problem it's getting pretty much to that line.
Yes, I did have tickets that I could verify with the airlines but OneTravel tacked on a BIG premium over costs of the underlying flights. I had a direct charge to my credit card from each airline on my itinerary and then a large charge directly to OneTravel. That's the scam part. So I think you have to be wary about their claim that they are a great source of discounts, you may find you paid more than you should have, or any small discount will be immaterial the first time you have to call support.
Another problem occurred at flight time. One of the airlines on my itinerary - I had no way of knowing this because OneTravel didn't tell me - had a fee for airport check-in. But due to the way OneTravel booked the ticket I could not check-in with the airline on-line. Ditto for bag charges, I couldn't pay on-line for the same reason and had to pay double at the airport.. However, this was not the reason for my initial problem with OneTravel. This is just another and later problem. The airline in question told me these things were the responsibility of the booking agent and that I should go back to them. I already know the hassle that that will be and I won't even bother to call them. I think that it's part of OneTravel's business policy to stone-wall everything and people just give up.
Stick to the reputable sites.