Here's a few notes in regards to your questions:
*PRO TIP* Don't feel that because you are a certain age you can't demand what you're worth. I was doing multi-thousand deals as a teenager on the international level right around your age actually. Some were closed 100% over email and bank wired. The thing is, if you truly have the skills and you know it, the client knows it, they can either take the offer or let them walk. The fact of the matter is there's always someone else that wants what you have to offer and is willing to pay for it. So don't settle for less than you're worth. At the same time be honest with yourself at least, if you're not damn sure you're worth a million dollars and you know it, they will know it, and you're not going to get that amount. If you're a teenager and they don't trust you, let them get screwed by the 80 year old "reputation management" expert who still hasn't heard of what the internet is.
--> Just to be clear, nothing against old people, just using extreme examples to make a point. There are many smart old people out there.
With that said, let me move on to my key points:
1. The key thing is being able to justify your prices regardless of the amount. If you can't justify the amount you probably shouldn't be charging that much or that little. This doesn't mean you can't have nice margins on your products or services, but you don't want to come off as a ripoff/scam person either. Set your prices slightly higher initially so you have at least room to negotiate. Everyone loves a discount so be sure to keep that in mind.
Sure, you might be able to get away with charging more than you should and if you can that's great, but you better be able to handle that dreaded question "So, what does this include" or "How are the funds going to be allocated". The last thing you want to do is look like a dumb ass or blow a deal because you price gouged without being able to back it up.
2. Don't be afraid to be affordable when you're first getting your feet wet. A
COUPLE cheap deals won't kill ya, and is a great way to quickly build up your resume to get the big money deals. Also, this doesn't mean settling for less than you deserve. It's better to walk on a deal then set the bar low and get stuck there.
---> 2b: Explain to the client that you are giving them a lower than normal rate in order to build your list of references. Ask that they agree to leave you a review if they are satisfied with your work. Last thing you want to do is stuck working for less than you are worth.
3. If you're good at what you do that doesn't mean do work for $1 (regarding point #2), just be fair about it.
--> 3b. If you feel your work is worth $100/hour then charge it. If they ask if you can do it for $50/hour tell them to take a hike (politely). Don't be a jerk if they ask for a few bucks off and you can afford to do so cut them a small break, maybe $90/hr or a limited discount as a new customer. If you really can't budge on the price, then don't and explain why you can't in a professional manner.
4. If you're going to charge premium prices be sure to offer a premium level of service. This means if you get an email outside of business hours by 5 minutes you can answer it, just don't make it too much of a habit to the point where it becomes expectations. Essentially you need some unspoken "ground rules", but just be fair and reasonable about things. The more seriously you take your customers the more seriously they will take you.