John, I do exactly what you describe. You do need insurance. This cost me £500 this year. If you don’t you can guarantee that the night your garage gets broken into you will have a £1k bike in your care and it will be taken. I know. Otherwise, working from home = low overheads. I got some grant funding to buy tools etc and to get some Cytech qualifications though I had to pay the VAT which more or less negated the funding. I would say that the business pays to run my car, 20% of my household expenses and leaves a profit of around £5k pa. I don’t advertise hard, mainly a website and word of mouth. I could do more and be busier. True, you get some crap to work on but also some good stuff. I have considered charging twice as much and doing half as much to eliminate the riffraff. If you are time rich, you can afford to do a thorough, bespoke job and you will get repeat custom.