With ~10% tax and 20% tip, that seems right on the mark to me. I guess it would be less in places without sales tax.
That was one of the really weird things I noticed in the USA when I visited recently: this bizarre tendency not to include tax in the prices. Tell me what I need to pay you, not what you're going to end up having received!
Couldn't agree more. There are lots of other nefarious tactics, like "resort fees" at hotels. We're the land of the fee, I suppose.