Yeah what our client ended up doing was making a shipping rule in ShipperHQ (their shipping extension provider) which adds that 27 cents. Then, on our invoices, we just wrote some text that the Colorado RDF is included in the shipping fee.
It doesn't "fit" the guidelines, but at least our client was okay with doing that. At first they were worried about being 'out' the 27 cents on each order so they were going to have us spend around 30 hours to come up with the solution I stated above which would've just been a huge waste. Spending thousands to save what would've probably been $50. It made no sense. I'm glad they found the work around with their shipping extension.
Hopefully Avalara will come up with their own solution in time, or Colorado will just have some lawsuits filed against them and they'll change their tune.
My developer also stated I was his only customer asking as well. We haven't implemented anything yet. I figured it was cheaper to eat the .27 per order than spend a lot of money trying to develop a solution. I am still hoping that someone comes up with a solution we can all use. I also agree that the $50 Avalara is going to charge will be way more than the actual fee. It seems pretty ridiculous to me that CO has done this.