Just out of curiosity has anyone ever sprayed their car with spraycans you buy form the autoshop?

I got some graphite grey metallic paint in a can from the autoshop, obviously primer and lacquer too. I tried it on an inside door (vertical surface, lots of contours etc.) and it turned out great! if i cleaned it and smoothed it it would look bodyshop new!

Anyway was considering doing this to the whole car but i know it'd need a good few cans of paint but as it's a one off i think it'll still be cheaper than buying an air compressor and spray kit and paint etc etc..

Anyway i'm happy with the result on the inside door and it's given me confidence to do the rest.

I'm a cheapstake and don't fancy a proper bodyshop respray lol

bad idea or good if i take my time?

(p.s. any estimates on ammount of cans needed?)