Need help figuring out a fair price

Hey gang, I need help figuring out a fair price to sell my, (get ready) my Mongoose Pro RX 10.9 and figured this sub could help me out, if not, could you point me in the right direction?

It's been a fun ride, but I ended up eventually with a Serotta Legend Ti that I really love.

The frame is Titanium, features mostly Dura Ace 7400 8 speed groupset and some nice little additives like a Chris King black on block 1" threaded headset and Brooks Cambium C13 saddle. Wheelset is a little newer Dura Ace with Carbon rims.

So Mongoose.. right? The frame is pretty spectacular, I've put quite a few miles on it. Rip it a part as far as a critique, I'm just hoping to find it a good home.

I also have a full Dura Ace 7800 that I can make work—should I sell it with that?

I was thinking 500-600 USD, but was hoping for a little guidance.

Thanks everyone.