Buying pre-owned from an AD vs. watch forums...

I'm in the market for a Datejust, which will be my first big watch purchase. I've been eyeing one on a forum, but the seller is not including papers or a box. The buyer does claim many references on the forums though. Today I went into a local jeweler and he said he can look around for a similar Datejust with the features I want, but he is quoting me a price about $500 higher than what I am seeing on the forums.

So I ask you, r/watches, is it worth the extra 5 bills or more to get a box and papers and be able to check the watch in person before buying?