The short answer is NO. It is incredibly easy to make a legit looking website.

Personally, I think it's less likely that LE would make a web site & even less likely they would keep it up.  Stings are usually just run an ad, arrest a few guys or gals over a day or 2, move on to other Police work.  
However, there's no GUARENTEE.  Might LE do this to investigate a high value target?  Perhaps, so the odds change...  
Presence of a web site, contents of it, must be added to other research like reviews to decide to arrange a meeting.
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