I wouldnt bother mate.
I watched my dad for many years doing bodywork and spraying. Its not easy! You wouldnt get the right finish without really good equipment, which doesnt come cheap.
& as people have said above, youll have dust all over the place! If its metallic, laquers not the easiest thing to put on too. Plus youve got the added cost of the paint itself, depending on what youve got is not particularly cheap.
If i were you, id let your uncle do it, but you could prep. the areas which need spraying for him. As M.B. said, prepping is everything - get it wrong and it will reflect badly in the end result. Prepping takes time, quite alot. A proper bodyshop would mainly charge for the time to just prep. the car, not so much for the spraying.
If i were to take my valver to the bodyshop for a re-spray of the entire car (its all stripped out inside & out, and the engine was taken out last night), it would probably only cost me a few hundred quid, instead of well over a thousand! This is because its all stripped out, masked up, and rubbed all over for a key, and painting is all thats left. See the difference?!
Youre choice mate but i personally wouldnt bother, and would just prep. the car yourself in the future if you need anything doing. Assuming of course you can use filler well!
Hope this helps,
Al