I have been repairing and sevicing alternators and Starter motors for 20 years now. It's my business but I have always done the work myself. I am now 55 years old and have always been in the motor trade. You could say I have finnished my aprentiship.
I can offer you the chance to have your Alternator or starter motor working again at a lot less cost than buying a new one and oftern quicker than buying one on line. You also get the chance to have your oridginal unit back which is very often a better quality than a copy from china.
In to-days market your alternator can cost a great deal of money and can fail at a low mileage with just one component at fault the rest of the alternator could go on for 100,000 miles or more.