Need help with details. Blk Sub no date vs new GMT master w/ date

[olliec420]

Dear Rolex experts:

Ok so I have a 2007 Black dial Submariner with no date. The store where I bought it here (authorized Rolex dealer) just gave me an appraisal on the Sub for $7500 and they said they would give me $4500 for it on trade.
They have a black face stainless with date GMT Master with the half blue bezel for sale for $8900.
I would like to offer them my black sub for a value of $5000 and $3000 in 100$ bills for the GMT master out the door and need them to resurface my Apple watch stainless so I can sell it.
Do you think I am way off here of does that sound like a legitimate offer? If not are we close?

P.S. I really really want a blue face submariner with date and the 2 tone gold and stainless band. Does anyone know what retail and a good negotiated price of one of those would be. Also is a blue face sub with date and full stainless band an option for Rolex?

Any info y'all can add would be much appreciated!

http://imgur.com/a/bwE9P