I have spoke with you in the past and we met at PRI. Our shops have some similarities as far as the kind of work we do. I am sorry to hear you are still struggling.
I completely agree with hiring someone at minimum wage. Give a kid a chance that is a total motor head who is willing to learn. This will free up some of your time. Teach and demand from him quality, and to do it right. He will become a valuable asset. Or if you can find someone experienced that can bring some business with or fill in your weak areas, that would help you.
Our chassis dyno took awhile to be busy, it is something you have to create a reputation. We started out only scheduling dyno pulls for Fridays and Saturdays..... Why? Word of mouth travels faster on those days in the performance area. It is just before the weekend and your customer will brag all weekend.
Another suggestion from our experience: Change your shop labor rate..... RAISE IT! Have two different rates. Have an hourly rate for your daily drivers, and a second, higher rate for performance.... and do not make excuses for the higher rate! Your experience and knowledge on performance is worth more than general auto repair rate. Our hourly rate is $90 and our rate is $130 for classics (older than 30 years) and performance. We take pride in our performance side of the business and you get what you pay for, a top notch job done by an experienced shop. With the higher rate, we have earned respect and the performance shop did not slow down this winter.
You have customers telling you about other shop's pricing. Are you comparing apples to apples? Do you take in the same clients? Secret shop the competition and find out for yourself. Don't go on the word of a customer that wants a deal, fire them and define the type of customer you do want in your shop.
(Sorry so long)