Dabone: Everyone here has given you sharp, effective and truthfull advice. In all honest, your work, effort, time and products that you use...when combined together are worth FAR more than $75.
To have a customer that you quoted this obscenely low price BEFORE you did the work, agree upon it, and then AFTER you finish for him/her to back out and say they wont pay you is a crime. I think you should make it clear and be very firm (but polite) from the begining (with all your clients) that you are offereing a ultra conveniant, highquality service (unparraleled by those generic detailers/crappy delaership detail shops), you charge more because you do a quality job.
Tell this schmuck about the Mcdonalds hamburger/Filet Mignon analogy....tell him that we must compare apples with apples interms of service pricing, $75 that you agreed was already FAR BELOW market value for the services he received.
It is absolutely pivotal to explain/briefly educate ignorant and arrogant customers like that PRIOR, and AFTER your work so that they can get a full scope of how thorough, unique and highcaliber you are...otherwise they may think your no different than the joe shmo who they used to pay $30 for a 'wash n wax.'
If ever after you spent your time with explanations, proved yourself in the quality of your work, and charged a ridiculously low price like you did ($75) the guy treated you like he did...i would politely yet FIRMLY drop him as a client, PERMANENTLY. Its not worth your frustration, time, effort and energy to work for an under appreciative cheap thief like the guy you mentioned.
Im sorry if this seems like venting, but i got pretty frustrated while reading your post that some people are that arrogant and rude.
Charge prices based on what you feel is fair compensation for your services (time, ebergy, products used...quality of work etc...) and be firm. Also, be sure to point out why you charge what you charge, and how you are different from the other generic low quality 'detailers.'
Goodluck and godspeed.
If i may ask too, how old are you? Perhaps he treated you like this because you are young/new to the business, and he thinks he can get away with stunts like he tried to pull?