The tax is 20% of the MSRP over 100k or $10k whichever is less.
For the Touring the pre-June 1st price is approximately $130k making the tax approximately $6k. Still a decent amount, but less than the $10k you were suggesting. I think you were using the post-June 1st price.
Please correct me if I am wrong.
To answer your question, yes it is a enough for me to downgrade to the Pure. I was torn before hand and was going to bite the bullet and pay extra for the Touring mainly to get the car earlier, but the extra tax on top seals the deal. I will be going with the Pure.