One thing to remember is you only have to book one person on points in the room - you can book everyone else on cash. We've used points for January cruises - one this year, and one scheduled next year - and we're using under 300 points for 2 adults in the room, and paying $500 for our DD cash. So, with the exchange fee, it's a $600 out-of-pocket 7-night cruise for 3, which really can't be beat.
We figure we have the points, we've paid for them so we can vacation with them how we want to. We're getting $8-$9/point on this specific cruise, so it's really not worth the hassle to rent and pay cash. And I only have 3 weeks of vacation a year anyway, so it's not like if we *did* pay cash instead, we could use the points at another time!
Amanda