Would someone kindly explain to me why I have to use 120,000 points for a one-way reward ticket to Europe when I am able to get a return ticket for 80,000 points?

I wanted an open jaw YVR-FLR cruise to FLL then FLL-YVR. The FLL-YVR dates are too far out to book, so I figured 'no problem, I'll book a one-way YVR to FLR for maybe 40-50K points and book a one-way FLL-YVR when available'. I was informed that the one-way YVR-FLR would cost me 120,000 points (talking J here) and that when I later booked the FLL-YVR it would by 40,000 points.I was also advised that I could not book a one-way YVR-FLR unless it was AC metal only--not * partners.

The agent advised me to book a return YVR-FLR-YVR ticket now and either use the return portion another time or just dump it. Then, book a return FLL-YVR-FLL ticket and do the same thing.

None of this makes any sense to me, but I'm sure the flight gurus on this forum will have the answers: how can a one-way YVR-FLR reward ticket cost 120,000 points when a return is 80,000? And do one-ways have to involve only AC metal?

I finally took the 80,000 YVR-FLR-YVR return option and I'll book the FLL-YVR later as a FLL-YVR-FLL. I still the feeling that something is wrong with all of this, though.

Cheers,
HTF.