Pfffttt, while you are at it, why not buy a tank of helium and inflate your kite that way... The Helium will reduce the effective weight of the kite and increase the amount of lift available to do big boosting jumps. Ensure you weigh your kite down on the beach though! Or, you can just tie your kite to a log and it will float like a kiddies balloon at the royal show.
I reckon the physical effort of lugging a heavy compressed air bottle down to the beach to inflate your kite has to be more than the effort to pump up your kite, and if at the end of your session you are completely shattered not only do you have to carry your kite and board back to the car, you have to deal with a metal cylinder as well!
Pumping up a kite is like a basic fitness test for kiteboarding... if you can't do that, then you probably shouldn't be out on the water...