If someone isn't totally committed, the chances are that they will not have treatments risk insurance & training, I don't want to pre-judge, but if you are only attempting to start a business 'on the side' then the potential customer is at risk.
I can see where Goran is coming from, I had a customer cancel us a couple of weeks ago because she had found someone to 'do' her suite for £40, who also did her gardening, the above mentioned situation did apply in this case, the guy had no idea regarding pricing.
We are fortunate to have many customers, so for us it wasn't a problem, but he could have taken the business from someone that had just invested everything in a new business venture.
Regards
S