By all means, pursue it! Get your "day job" and grow your hobby. At one point I had to work 3 jobs to get by. Do what you have to do, and you'll eventually get there. But it all depends on you and how hard you are willing to work to get there. As far as what to charge now, while you are starting out? That's a tough one. You need to do some research and try to find out what people are paying the "pros" to do car portraiture. Try to avoid doing it for free, it sets up a more difficult road. Like I said before...the quality of your work will spread by word of mouth, but so will your prices. I tried raising my price$2 for setting bulk diamond earring studs for one customer I gave a great price to, to get them as a customer, and I lost them for over two months. They came back because nobody matched the quality of my work. So if you start offering free shoots, and the free shoot customers refer you to others, the other will expect you to be free as well. It's all kinda tied together, isn't it? I think you'll be able to figure it out as you go. You get a customer, have to drive 20 miles/kms to the location, or you have multiple locations, or you have to do it over a couple days for the "right light" or sunsets, and you spend 6 hours getting enough shots for them to pick from....what do you charge? Eventually, you are charging for you hourly wage, petrol, car insurance, travel time, your gear, time spent editing, your website...and any other overhead you have factors in. Again, I am not discouraging you. You didn't ask easy questions, and there aren't real easy answers. Best of luck! Hang around here, post photos for critique! There's some really good cartographers here that can give you tips, tricks, and suggestions.