Just wondering... how long have you been into photography..?
You are better off with nicer glass on a cheaper body rather than cheap glass on a more expensive body.
I bought a D40 as my first SLR camera which was back in January. I've been working on buying more lenses.. and then plan to upgrade to a D300 if I feel my skills are up to par and I deserve it.
As others have said, Its not how many FPS the body has, its how quick the glass is. The lens is the 2nd most important part of the camera. First would be the user.
And majority of a picture is the person behind the camera and their experience and knowledge.
You need to put yourself in your dads shoes and look at it through his eyes. Most kids will want something.. and then grow bored with it after awhile. That is probably what he believes. However if all this money is yours... you earned it yourself... Then well.. its your money... Spend it how you wish.