Ok I will bite..
If you want the full frame advantage and dont plan to do video, BUY A 5Dc! Its a Superb camera and can be found for under 900$! It will complement your 7D perfectly and you can decided later if you REALLY want a 5d3.
It is a great cam... or was... I sold mine a few weeks back. The ISO performance of the 5dc got beat at 800/1600 by a T2i I borrowed from a friend, telling him how nice FF does on ISO... boy was that awkward when we compared shots... but it is an FF sensor.....
I Disagree. The 5Dc has the exact same ISO performance as my 7D, just full frame.
Even if ISO performance is same with the 7D/T2i ... a lot of the FF Advantage is gone. What you are left with is more OOF blur, the width/length advantages is a wash. Plus the additional cost of EF lenses needed for FF... I think the biggest advantage FF has is better ISO handling, if it is the same as the T2i/7D... then why bother?
Quite simple, The thread stated that newjerseykita already had full frame lenses. So when he asked for a camera to START into the full frame advantage, Such as Nice OOF blur I Highly recommended the 5D classic. Its half the cost of a 5DII or the 3500$ price tag of the 5D3 but would get Kita into the full frame world.
Really, I could buy a used 5Dc + 50mm 1.2L at the price of the 5DII body or even the 5DIII body. Also, I've shot with the mark II and is a great camera but Not for 2000$. (its AF is essentially the same as the 5Dc). With modern noise reduction programs like Lightroom, I do not hesitate to shoot at ISO 3200 on my 5Dc.
IMHO, For someone who wants full frame but Cant justify a MKII because its AF but is wondering if the 5D3 is really worth 3500$, The 5Dc is the obvious choice.
I'd advise him to get a 5d2 for $1500-1750 range. If the only thing he did was portraits then I too would recommend the 5d1, but the ISO of the 5d2 leave it in the dust for other applications. Plus it has AFMA/Liveview/22mp/video etc. I was researching dpreview and snagged a couple of ISO3200 shots of the 5D, 7D and 50D. They are all close, but the 5D at 3200 is closer to the 50D. The 7D is slightly better than both with lower Chroma/color noise than the 5D1. Especially check the Black area...