I worked at a place where I hired seamstress' and yes, you do have to be careful. But I would say that the woman that I worked with who home sewed were awesome. They might be able to supply you with names and phone numbers.
Many people make the mistake that they think an outsider can do something as quickly as they do.
Remember that you are familiar with what you do. So when you create something for the first time, time yourself. See how long it takes you to do it and how many you can get out in an hour. Use that as a foundation for your pricing. That doesn't mean that it will be your final price but its a place to start.