Upgrade from 5D I (classic) to mark 2 vs Buy new L lens

Hi I am at the point where I want to try to upgrade my dslr equipment. I currently shoot with a Canon 5d mark 1/classic (12.8 MP) that was handed down to me. It is extremely clean and in great condition, and the neighbor who had it before me was a landscape shooter barely used the thing.
(He's also an investment banker working 80 hours a week so I know he had no time to take pictures).

I have used it for the past year and put maybe 7 to 8000 actuations on it and he told me he put about 3,000 so it is a fairly new camera.

Now that brand new mark 2's are selling for around $1500 to $1600, I am wondering if I should invest in a new mark 2 before they sell out. Because my 5d classic is in such great condition(without a single scratch and fresh black paint on hotshoe), I am thinking I could get around $700 for it. So I would be paying about $800 extra for a brand new mark 2.

or

I could invest in a telephoto L lens. I currently use the tamron 28-75mm zoom and canon 50mm f1.4 (which is practically glued to my camera). I am thinking of the canon 135mm f2L or the 70-200mm f2.8L. I would be buying them used of course.

or

I could make a crazy move and purchase a brand new fuji x100 which Ive been eyeing since its release.

I am into street photography. I live in an urban setting and the 135mm f2L would be for taking street portraits. The fuji x100 would be nice so I dont have to carry around my heavy dslr everywhere but it would overlap (somewhat) with the canon 50mm f1.4 in focal length. OR I could invest in a mark 2 but I would HATE to see it depreciate within the next year. My canon 5d classic is pretty much done depreciating so it wont make me as sad.

I am a 1st year dental student. Yes I am in the library all day, everyday. But I always carry my camera so I could take photos while I am outside taking a break, or walking home. This would be a lot of money for me since I am already like a bajillion dollars in debt. However, I like to destress this way. Right now I know what my heart wants, but I want to make the most rational decision....so ANY suggestions are very welcome.

Thanks!