You must only travel with a staff discount or free....
But that doesn't mean I don't know that most airlines nowadays sell most tickets on a one way fare basis (i.e. usually half the price of return). I'm not sure where you're based, but in the last say 5 years, whenever I've bought domestic tickets in America, intra-Europe, Oz and NZ, they've always been one way fares only. The only time I've seen one-way tickets being ridiculously expensive compared with return tickets was on a couple of legacy airlines who obviously haven't yet responded to market forces (such as Alitalia) and I think I remember SAS and Swiss being like that the last time I checked - but they may well have now updated. You can certainly buy transatlantic flights one-way at half price of return (promoted heavily outbound US) and I've bought one-way tickets between Europe and OZ on BA/Qantas at very reasonable prices too. The only problems you might run into are immigration issues if the country requires you to have a confirmed outbound ticket within 90 days when you enter.
I suggest you check with a travel agent if you feel you can't find good deals on one-way fares. (Or you could marry a hostie/airline pilot and travel with them!)
Regardless, you'll probably still need to show your boarding pass when boarding...
