As far as I know I am the only dedicated storm and screen repair shop in this area. There are a few other places that can do repairs, like hardware stores and auto glass shops, but mostly they use a part time person or a minimum wage employee who doesn't have much experience.
I charge $38/hour plus I mark up materials 100%. I can repair a typical screen or storm in 15 minutes.
So that is $9.50 labor and $2.50 in screening for a total of $12 and tax. With my materials markup this gives me $43/hour, great money if the business was steady.
The hardware stores and auto glass shops in the area would probably charge double that.
You could either advertise that you charge half the price of anyone else or you could charge $20 and advertise that you are the cheapest.
I offer two hours of training, tips for starting a new business and tips for repairs.