Feedback on possible trade

I just made the jump from 7D to 5D MKIII and I'm selling my EF-S lenses and have a trade offer I'd like to get some thoughts on. My current lenses are 24-105, 85 1.8, 70-300 IS. I like the 70-300 but really want a 70-200 variant to really shine on the new body. Now I know the 70-200 2.8 IS MK II is the holy grail, but it's pricey and would take me at least a year to save up for it most likely, especially after what I just spent. I'm also not a pro, do some side shoots for family and friends but mostly my kids and sports and what not. I do plan on keeping the 70-300 for a lighter weight travel zoom and using the 70-200 for indoor, low light, sports, etc. So the trade is my 17-55 2.8 IS + $400 for a 70-200 2.8 IS MK I. I rented the MK I for my daughters first recital and was very impressed. I know the MK II is better, but it's get this now for little out of pocket or wait. Thoughts? What would you do? Thanks in advance!