Should I trade up to get a GMTIIC?

[suntaelee]

I currently have a 14060m Non-COSC:

I just recently sold my Baume & Mercier Classima and came up on some cash. I was originally going to add around $400 to buy the Longines Moonphase I always wanted:


But now, I saw a great deal from a trusted dealer. He is willing to accept my trade plus more cash (around $3k or so) for a BNIB GMTIIC.

What should I do? Do I just have 1 Rolex or keep the sub and get a watch I was eying before I bought the sub? The reason I still wanted the Longines was cuz I can wear it with brown shoes or whatever.

Help me decide? Thanks!