I do this as a side job most weekends, not all, but most. And most of the time once we get into talking about what that person truly wants..we end up doing a full correction. I've been told I'm cheap and don't cost much..but hey this IS fun for me after all (don't tell anyone that cause I'd probably do it for free anyways!). As far as prices are concerned here's my thing immediate and close family is free, don't care what it is, its free regardless. I'm also not in the car washing business..IMO that's not detailing thats MAINTENANCE, and I'm not your maid, wash your own damn car lol!! Friends extended family depends on condition, what they want etc. For a regular customer its BASE $200 for a car and BASE $300 for an SUV or Truck. That includes wash, clay, polish, and wax or sealant.
Interior is $30-40 more and I usually throw in the engine at no cost, obviously tire and trim is included as well....as I said I've been told I'm cheap..I know I'm cheap..this is what I do for fun and while I have a full correction or close to it almost every weekend I still consider myself "starting out" business wise that is. Keep that in mind as well, you can't charge top dollar for something you have no "cred" on. And personally I am JUST GETTING STARTED, READY TO SET IT ON FIRE!!! But there's still SO MUCH to learn.
Let your work speak for itself, I'll tell you there's no greater feeling than seeing that look of astonishment on the owners face, that's by far the best part!