T3i: Sell or hold off?

hey guys,


for a while I've been jonesing for a 6D...Canon offers a refurb deal on just the body for
about $1330 for students.

My photog buddy and pro shooter talked me into listing my T3i and accessories for a rather outrageous price of $850--
as the first step of getting me into a 6D.
(T3i, 17-85, 4 batts/charger, 2x 32 GB cards, UV and polarizer, orig box, box candy, carry bag).

I didn't think I'd have any interest but I suddenly have a standing offer for $800.

This leaves me a fair bit short for the 6D. My friend has generously offered to let me use his 5D2 (his 3rd rig) for a while so I can save up.
As a college guy going back into school and not generating a ton of cash these days, I'm hesitant. I have some other things for sale but they're not really moving.

I realize I have a buyer at a really great price, but I also work as a PT product photog, and being cameraless and on loaned gear makes me nervous. The lens is worth $200, the body maybe 350, and the accessories aren't high dollar stuff. It's all in decent shape.

Thoughts? Experiences? Take the leap for that sale price or stand pat and play it safe on this one?