Not if the person attached an NNID, and now, to access the shop, you need to add the NNID, possibly negating the Ambassador claim.
People seem to forget that the only reason one would want a sub version 4.6 unit is for piracy (oh, I'm sorry, "Homebrew". Call me when there is some). That's a very small market. Average joe consumer isn't going to pay more for that. They want the cheapest price. Period.
Not to mention you seemed to skip over the part in the description that mentions the unit shutting off randomly when hitting ABXY, making it a damaged unit.
I buy, sell, and trade used games locally. Ambassador units mean nothing to store owners, and most people who MAY have heard of them don't always understand why it would command a higher price. It's an older system, and given the market right now, less interesting than a 2DS or XL. Mention firmware and the majority of consumers get a glazed look in their eyes. Very few even know how to turn streetpass on, from the units I've seen.