PAM00051 Question from Panerai rookie

[AndTylerToo]

Hello! Hoping all you Panerai experts can give me some pro tips for what to look for when purchasing a pre-owned a PAM00051. I see that there are a number available online (mostly without boxes and papers) for around $5-6k (which seems reasonable given other price increases over the past few years - please correct me if I’m wrong) Any red flags to look for re: counterfeits, inauthentic parts, etc.?

This one looks legit to me but I’m really flying blind here brand-wise. I only have purchased Rolex and Omega preowned.

https://lwmitalia.com/watch/panerai-...full-set-1999/

Thanks!