What types of customer market are you looking at? Homeowner, landscaper, plumber, rental management............? Each one has their own unique needs and can be better served with different types of equipment. Full or part time, you have to remember that your customer is your boss. And some of them can be extremely hard to please. The other tough one, at least for me, is bill collecting. I hate having to follow-up on people that haven't paid. And you can't extend what you can't afford to pay yourself back.
Let's say Joe calls and wants some work done. Before that job is paid, he has some more work. Second job is done and first still isn't paid. Promises and promises, still no money, but he has a settlement check coming this Friday. So how about doing this third job and I'll pay for all three on Monday? Next thing you know, you've got a big chunk of your time and money invested.
And, oh yeah, even a cashiers check can bounce.
Not to be negative, just some realities of doing business today.