I ran a part-time computer business when I went back to school.
Some of the repeating trends:
No matter how many times you repeat your hourly rate they will forget, after having you there for 6 hours fixing everything else besides what you came over prepared for, they will insist you only have been there 15mins and the rest of the time was conversation.
You will have at least one customer go to a closet when you hand him the bill, returning with various 286 and 386 machines and parts insisting the trade he is offering is worth at least $5000 since he paid at least that much for it and it's only been a 'few' years.
You will have to battle with 'their computer expert friend/relative/child' who knows so much about PC's yet for some reason they still called you.
You will have quite a few 'experts' you have hired you and second-guess every move you make or constantly utter 'Be careful with that you may break it'
After upgrading their CDROM they think the CPU upgrade is free two months later since 'you already billed me once to upgrade'
'You were only here a little while, I don't feel I should be billed anything'
You will have a ton of people wanting to choose their own hardware despite you telling them incompatibility issues are rampant with some. They have a $9.99 piece of hardware they found when the average you found was closer to $75...after 6 hours of trying to make it work at their request they insist they shouldn't have to pay because you couldn't get it to work, which was precisely what you told them 6 hours before.
