How do I convince my parents to buy me a DSLR for videomaking?

Ok, basic summary of the situation:

My parents want to buy me something meaningful for my 21st & are willing to spend a fair amount on it. Dad's not convinced a DSLR is meaningful, useful or lasting, or that I even need one (thinks a new camcorder or my webcam should be enough for now). He doesn't know too much about cameras so not sure tech talk could impress, or how to explain the benefits so he can understand.

I think I need one, am an amateur videomaker, going into the 2nd year of a media production degree next year & wanting to make videos/TV/films for a living in the future.

I've saved lots and if needs be will spend all my money to buy it all myself if they don't, and am happy to make a deal to split the costs, say they just buy the DSLR body & I buy the rest.

Dad knows all this but he's still not convinced. Any ideas what I can do? Sorts of things I should talk about?

I'd be okay buying it all myself but I also need to save for a new computer - this one's pretty old & slow, and I need a good one that can handle heavy duty editing, at least starting next year, and that could be another £1200 or so.
I'm currently taking a year out of the educational system to do what I want, and I'd hoped that would be practicing videomaking and getting lots of enjoyable work experience at relevant jobs. I don't want to spend it doing full time at a job I don't care about, not learning much about filmmaking and just saving to get that computer in time...
Asked Oct 07, 2013
Edited Oct 07, 2013

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