I was on Freedom at the beginning of December as a solo-cruiser. Yep, it's painful to pay double, but OH SO WORTH IT!
FYI, if not set on one particular ship, RCI publishes "happy hour" specials each week. Some sailings only have a 150% single supplement. You can find the specials (published every thurs or so for booking by the following tuesday) at http://www.creative.rccl.com/sales/h...r_rci_tues.pdf
I also happen to have a great travel agent. The prices are the prices, but he is always on the lookout for bonuses and upgrades, and has very good RCI connections. PM me if you would like his info.
I'll make a suggestion though.....I booked a Promenade cabin on this last sailing, as I thought it would be a good way to save some money without doing a totally "inside" cabin. Some folks love this category of cabin, and it was indeed very nicely appointed. I'll be loathe to book another cabin without a balcony (or at the very least an ocean-view window) ever again, though...no matter how much of a premium I have to pay. I just didn't feel connected to the sea in there, and really missed having my morning coffee on the balcony, watching the sea go by.
Anyway, good luck in finding a deal. You will love the Freedom (I went on her twice last year, I liked her so much!