I shoot portraits and weddings.
My old setup:
T2i, Sigma 30mm 1.4, Canon 50mm 1.4, Canon 100mm 2.8 Macro, Canon 70-200 F4L IS
In the past 2 weeks I decided to go full frame, so I kept my T2i and 50 1.4 and sold all my other lenses for a grand total of $1800 and in the past week I've purchased:
5D Classic, 4x 8gb 30m/s CF cards, 3 batteries
Sigma 85mm 1.4(Returned it, couldn't focus accurately past 5-10m)
Canon 35 f2
Canon 85 1.8
Samyang 35mm 1.4
Canon Ee-S focusing screen
Costing me a total of $2835($1035 net). I LOVE this buying used stuff. All my new gear is used, but it's all in incredible condition. Literally looks new, works perfect. All of it even came with boxes and warranty cards.
If there's anyone out there that DOESN'T buy used, reconsider. Seriously. It cost me $1035 to go full frame, buy 2 incredible L lenses, a sweet manual focus lens with amazing colors and sharpness, and 2 more fantastic lenses to fill the gaps. If I had bought new it would have cost $3100 just for the lenses, and since you'd have to buy a 5d mk2 to get a new full frame body, you're looking at $5200. Buying used saved me $2365, $919 if I had purchased a used 5Dc and new lenses.
Now, when my girlfriend says, "I know it was a lot of money... but I got it all at TJ Maxx!" I can remind her that, "I know it was a lot of money... but I got it all used on forums!"