As the cost is all about the dimensions, I suggest you do a serious KD (knock down) of the bike. That includes removing the fork and, after seriously careful wrapping, packing it inside the frame triangle. Etc. Somewhere, I think MiamiJim has a nice set of photos of packing.

Anyway, you should cut the box down to the smallest you can get away with and still have the bike well padded. You cannot hope to just stick a bike in a box and ship. That will cost a small fortune. Or, as you find, it's just too big to handle.

Try trimming the numbers until you get one the calculator will accept. Even just to experiment.

Good luck.