Is it better to purchase additional lenses for my t2i or start fresh with the 6D?

Question

I'm looking to get into wedding photography.  Is it better to purchase additional lenses for my t2i or buy the 6D body?

Answer 1

I am in line with cicopo and TCampbell.  And, yes, this is the most important statement, "Keep in mind YOUR skill is first and foremost."
Also, I agree, lenses before body, however, sometimes appearance is everything.  Doing this for so long I think I have seen about every possible circumstance possible but it never ceases to amaze me when a new one arises.
For several years I had five XTi's that I loaned to my assistants.  But a few clients I interviewed have asked what equipment I use.  "You don't use Rebels do you?", was a common question.  My uncle Bob or aunt Bobette can do that for free.  Or the neighbor down the street from me has a Rebel.
Bottom line is, how important that first quote in this post is.  You must offer your customers something they can not get for free. Make it worth their money.
One is your eye and talent.  The ability to see the picture before hand.  And, yes, equipment that the uncle or friend does not have.
I am retired now and don't actively seek jobs but I do a few .  I use all 1 series cameras plus a 5D Mk II along with a 7D.
I generally have, at least 4 or 5 cameras at each wedding.  The 5D gets a 24-70mm f2.8. One 1 series gets a 70-200mm f2.8 and these two cameras do 75% of the shooting.  The 7D is on a tripod with a 100-400mm zoom on it and it sits at the back of the church (or venue).  My assistants have my other 1 series (one or two) with the 24-105mm f4 on them.
Another example of what perception can sometimes be, is what happened while I was at a friends studio the other day.
A lady, new customer, came in for pricing and after a short while of looking the place over she left. On her way out she commented, “I thought you used professional equipment!” We were dumbfounded at that for there was a 5D Mk III with a EF 85mm f1.2L II USM on a tripod that was in plain sight. About the same moment we both noticed a Tamron pinch style lens cap on it. She must have seen that and assumed it wasn't a Canon lens. Some photographers will buy Tamron pinch style lens caps and use them instead of the OE Canon. But the point is just beware.
It makes a big difference if you are doing this for funesy or you are putting groceries on the table. 
EOS 1Ds Mk III, EOS 1D Mk IV EF 50mm f1.2 L, EF 24-70mm f2.8 L,
EF 70-200mm f2.8 L IS II, Sigma 120-300mm f2.8 EX APO
Photoshop CS6, ACR 8.7, Lightroom 5.7