Best way to avoid paying high one-way fares is to purchase a return (with the return leg several weeks later at an off peak time) and not use the return. I've just had to do this and saved 400 Euros in the process. Once I've flown the 1st leg, and before NOT flying the return leg, I cancel the return online. No refund, but that's OK as it's just saved me 400 Euros. It's really time for the majors to charge more realistic one-way fares as do the LCCs.