Short review: go if you happen to be in Nashville. Otherwise, I would not consider it THE reason to go to Nashville. Put it on your itinerary between The Hermitage and Tootsie's Orchid Lounge.
Not that it is not interesting a fun to visit. It is, if only for the cool Marathon Motors factory that it is housed in (I really would have enjoyed seeing more of the actual building). And, to be fair, for the items that were on sale, I was surprised by the prices - I expected them to be somewhat inflated since, presumably, they had been "picked" by either Mike or Frank (although there is no way of knowing that, except by the assurances of the staff), but they were not overly done.
But . . . a lot of the items bore the "NFS" tag - "not for sale." And really what was the main point of sales there was merchandising equipment for the TV show and the store. I thought I detected a shark jumping when I saw this:
"Mike has one!" So, isn't that enough to make you want one, too? A t-shirt I can see, but the iPhone case or the mouse pad is getting a twee too much. There were even work gloves that (if I remember correctly) had the store logo for $9. Harbor Freight Tools carries them much more cheaply - gimme a Sharpie and I will make my own.
I had expected to be asked to put my camera away, but no one did and plenty of people were taking pictures on their cell phones and iPads.
Stop by. If you really need a souvenir, take a picture. Otherwise, as I advised one gentleman who thanked me profusely for this nugget of information, I will see you this weekend at the 127 Yard Sale, where I hope to do some serious picking.