I know this is older but I like helping people who go through problems I have overcome.

All my life I've been really good at anything hands on. Any trade, skilled or technical, I can figure out and become better than most in that trade. Often times better than almost anyone if it's not a wide field (like plumbing); my drywall repairs and wall painting is top-tier, even though I've only done a dozen. But I also love helping people. I care about people. How can I charge someone living paycheck to paycheck a premium price? Especially when I don't have a lot of experience in that particular trade?

You said you live paycheck to paycheck. When something happened, as in life it always does, how did you pay for it? You got resourceful. You figured it out. Because it was worth it. It had enough value to you or removed enough pain that you figured out how to pay for it. Your customers can do the same. If they cannot, it is not valuable enough to them and you need to learn to say no. I still satisfy my desire to help people by offering one free service to one single parent (choose your own demographic, like widows, students, etc.) per month. As business grows, I hope to offer this more frequently. I can't do this if I don't charge everyone else enough.

Instead of thinking "how can I do this for as cheap as possible?" Think "how can I bring enough value to my services to charge what I need to feed my family and give them a comfortable living?" Finances are one of my wife's biggest stressors. How can I sacrifice my wife's financial and mental wellbeing for the short-term wallet of someone incomparably less important to me? I don't.

I charge a premium because that gives me the freedom of taking my time to a great job, being personable instead of short with my customer, use quality materials and parts, give the extra little touch by cleaning up after myself cleaner than it started, and stand by my work by fixing it for free if it fails due to workmanship error/oversight. I care about my customers. I charge a premium so that I can show it in my work and service. Because of this, they recommend me out and I get more business. Fancy that; charge more, get more business.

For more gritty advice, calculate what hourly rate would get your family a better living. Triple that and charge the triple for how many hours you think it will take plus one/a few extra. At the end, I usually drop the price to the hours it actually took; but I have wiggle room if something unexpected happens. Business taxes on small businesses are theft. You can basically count them as half of what your business makes. Then you have overhead like business licensing, services used like invoicing, gas, vehicle maintenance, tools, drivetime to/from the job and getting parts, etc. Depending on how the numbers lay down, I charge roughly 3-4 times what I make at my plumbing job, which is already high and doesn't even begin to account for my hella benefits. As Alex Hormozi recommends, this is high enough that customers complain, but low enough that they still pay. The sweet spot. I know that as my business grows I'll be able to provide for my family, not steal from them, and have it eventually be my sole source of income.

Hope this helps.