I bought an Hermès Kelly bag from TRR and the experience was absolutely fantastic except for the packaging. The bag was well priced; I had it authenticated before I purchased of course; the customer service was kind enough to be open with me on the phone about two Kellys that were available and the differences; and the bag when it arrived was fantastic.
I have a house in a state with no sales tax on wearables so I had them ship there; no problem and no tax applied. Only issue is they shipped the bag in its dust bag alone in a box with almost no padding. TERRIBLE packaging for a bag over $5K, fortunately no damage. If I bought again I would be specific about packaging to ship.
With regard to authenticity, I would always have an item authenticated prior to purchase if possible. Fakes are getting so sophisticated that only a real expert can tell, and the so-called authentication experts at 90% of the resale places are NOT expert in every brand. TRR,
Fashionphile, and Portero have all sold fakes unknowingly in my direct experience.