Got an offer for my Daytona

[versatile1]

So a guy I know wants my Daytona it trade for a couple of watches he has.
He's offered up a 1680 sub that has just gone through a complete service and looks to be amazing for a 40 yr old watch, along with a bnib sub no date ceramic.
He has asked for 1800.00 back with the Daytona
His ask on the 1680 is 6000.00 and the no date 6600 for a total of 12600 less 1800 is giving me 10800 for mine, question is, is the 1680 really worth 6 g's

I'm not sure what to do!
If I met in the middle at 900 back would I be silly to do it?
The 1680 comes with service papers and warranty from Rolex canada