Advise a tenderfoot, please.

Am being offered a Rem Model Seven from the factory custom shop. It's a hunting rifle configuration. Some questions:

Are Model Sevens good?
What does the custom shop do to those guns that makes them 'custom'?
Seller is asking 800 for a rifle that retails for 1300. However, in asking around, people have told me to save my money...that the custom shop rifles aren't all that special, that I'm better off with a secondhand Model Seven or 700 or 70,and put the
extra money into a trigger and/or accurizing job.
Is that true? I do like the rifle, and if your input is positive, I'd like to buy it.
Seller states that the rifle is unfired.
What is a fair price to offer?

Thanks to all