Pre-owned Rolex sub pricing question (black TT 16613)

[jbpats0823]

Hey all,
First post but not first Rolex. I am in the market for a preowned Sub 16613 TT black dial. For years now I told myself a vintage root beer GMT would be my next purchase but instantly fell in love with the 16613 after I saw it in person this past weekend.
I am having a little difficulty guaging whats a fair market value for a pre-owned model. Unfortunately I can't afford a new one at this moment, this was my GMT budget and a new 116613 goes for 12k.
I noticed sellers are asking around $6500 on average for an early-mid 90's model in good condition with box and papers, $7000 for a late 90's and $7300-8300 on average for anything pre rehaut with the gold clasp.. with very little wiggle room for negotiation.
It could just be me but that seems very high especially on a current model that is still in production and overall not extremly popular (from what I can tell the blue dial 16613 is king to many who are fans of this particular sub).. and more importantly none are really selling at these price points.
Having said that, what is a fair price point for this model? I've never been much of a haggler, but I also don't want to spend 20% more then I have to on an already somewhat expensive item.