Why pay someone to do a simple job you can do yourself.
Pull out the mouth inflator blow it up and leave overnight. Unscrew the inflators cylander and weigh it to make sure it has still got air inside, some have the empty and full weight stamped on the cylander. If it doesn't have the weight you will need to buy or find out the weight a full one should be.
If you feel you would like to change the cylander then just go ahead and inflate with the old one.
This is the method we get recommended over here as a service is about the same cost as a new jacket.