Excellent. Costs shouldn't be bad at all as there is no permitt required and no fees. It would be nice to share the taxi from the airport and transportation in a 4 x 4 up to the first hut. I don't think either should be so bad price wise. From what I can tell from reading other's trip reports, it looks like a week would do it including getting there and away. Check out the info. on this site.
That time frame sounds fine, probably arriving 26 and going from there on would be best for me as I am being recruited for Christmas festivities. I'm not set on that though- if prices are best to fly on X mas day, I'd do it.