I'm currently looking for employment for summer, but as I wait, I'd like to build some PC's for money. Problem is, I'm not sure how I should charge for them. Should I do it hourly? Should it be a percentage of the cost of the PC? Should it be a flat rate? I'm not sure which one makes people the most comfortable while making me a decent amount of money without ripping them off. Currently I'm thinking of simply taking parts the customer has bought and assembling them. Would buying the parts myself, building the PC, then selling it have a higher margin? Any ideas?