[NF] Microsoft Surface Pro 3 for sale -- what's a good fair price?

I've been needing a replacement laptop for awhile now. My old Dell Latitude 5530 is about 5-6 years old I think. Got a buddy of mine (so friend's discount to be included!) who's got an extra Windows Surface Pro 3 laptop he's willing to sell me. Told me to tell him what's a fair price. He's not a techie. Hardly used; maybe 2 months.

Specs: Microsoft Surface Pro 3 Intel Core i7 6650 U CPU @ 2.2GHz 8 GB RAM 64-bit OS Windows 10 Pro "Pen and Limited Touch Support" 238 GB hard drive No CD/DVD docking station with plenty of ports

Thoughts?