Are you kidding? (just asking ...)

But since it's your first post, I'll take it that you're not a frequent flyer and give you a few helpful hints:

1) A 1-way ticket from UK-US could be really expensive. Don't know if that would offset the "savings" you anticipate with the US-UK roundtrip flight.

2) With a one-way international ticket, you are looking at a lot of security screening & red flags (arrive extra early at the airport). By the way, try not to buy that ticket with cash

3) I was going to say it would be "impossible" to sell half a ticket on eBay, but there are always suckers out there who will buy odd stuff without realizing they can't use/redeem it.

4) However, there is no way someone can travel internationally from the U.S. on an airline ticket that doesn't match the name on the passport. Forget INS/Customs, the airline wouldn't even board the person.

Hope this helps, even though I'm sure it's not the answer you're looking for.