Simple solution for you. Use this URL for free shipping:
www.cigarsintl.com/freesp8
I don't see the point in complaining about the sales tax. That's not something they can just waive.
As far as shipping a humidor, I would think part of that cost goes to overhead like packaging materials. I mean, a large flat rate box through USPS is 15 bucks.
The only gripe I have with CI right now is they did away with their cigarmageddon section. But I only order cigars from there.