Shipping from Dr. Diff in USA?

...Example, when I bought my TTI headers, it actually cost me substantially less to order through my local dealer than direct from TTI.
I bought my TTI exhaust system direct and it was $100 cheaper than the dealer who is 3 hours away from me. So yes, it does vary. You would think that they would bring in a larger shipment and get better freight deals. If so they don't pass the savings on. On occasion I buy from National Moparts but their prices are often pretty steep and I still have to pay freight.