Roli,
maybe you look again at the 'frames per seconds'
30D: 5 per second
5D: 3 per second
... and review your statement 
That simple feature is very important to most sports photographers. What does high frame count bring you if the speed is 40% slower?
The 5D is better in many respects than the 30D, but sports photography is definitely not one area where it is better.
Rather look at getting a used or refurbished 1DII or 1DIIn!
That should be available now for the price of a new 5D and will be 500% more useful to a sports photographer.
Plus, IMO a used 1DII should still be more robust than a new 5D...
Best regards,
Andy