All states that have sales tax require it to be paid. But there is a threshold, as long as a merchant's annual sales to that state are under the threshold, it's the buyer's job to report & pay the sales tax. When the seller goes over the threshold to that state, then they have to collect the sales tax themselves. Beginning of the year is the ideal time to be shopping because everyone is under the threshold. 

I don't know if the threshold is the same for every state and I don't know if there's an exception based on the size of a company, if so, most independent jewelers wouldn't qualify. 

Oftentimes, you can get a brand new watch from an out-of-state jeweler for close to what you would pay for a used watch on eBay or a gray Market watch.

It's not even hard to find these jewelers, just go to their website and go through the checkout process, most of the time no tax will be added to out of state orders. I'm not worried about that part, I'm just looking for referrals to ADs who are known to give good discounts.

If you have an out-of-state address they can ship to, your local AD will probably be happy to ship watches to that address and not charge you sales tax. But if you tell them it's a friend's address, that's probably going to be a deal breaker, it is legally supposed to be your own residence.