How Much Should I Charge For A Single Composition?

Basically, I compose soundtrack type music on FL Studio as a hobby mostly. Mid of last year, a friend of mine asked me to compose a score for his short film which I did for free as he said he didn't really have a budget and I figured since it was my first time anyway for a professional job and he is a friend, that I wouldn't mind doing it for free. He clearly was happy with it because he just hit me up again to write another composition for a commercial he is doing.

He only needs one song, maybe 2 - 3 minutes long. I wanted to know how much to charge for it? Keep in mind that I'm not a professional musician and it's all self taught. How much would be reasonable?

Thank you.

Is he getting paid for it?  (Then you should too.)  Good for you!  It's okay to gradually increase your prices as you go and be inexpensive now to attract more work later.  Just be really careful that you don't get yourself stuck in a hole that way as the inexpensive composer.  If someone knows you only charged x amount to their friend a year ago, they may argue with you when you want to charge them y amount later.  Charging less than you are worth drags down the market on everyone's work.  So charge what the piece is worth for it's quality and it's length.  The fact that you are self-taught and still learning shouldn't matter.  Just how good the work is right now. 

Is he getting paid for it?  (Then you should too.)  Good for you!  It's okay to gradually increase your prices as you go and be inexpensive now to attract more work later.  Just be really careful that you don't get yourself stuck in a hole that way as the inexpensive composer.  If someone knows you only charged x amount to their friend a year ago, they may argue with you when you want to charge them y amount later.  Charging less than you are worth drags down the market on everyone's work.  So charge what the piece is worth for it's quality and it's length.  The fact that you are self-taught and still learning shouldn't matter.  Just how good the work is right now. 

Thank you! He isn't getting paid, he is doing a commercial for a competition if I'm not mistaken. The problem is I don't know what's a reasonable price and I can't seem to find anything about it online as well. I think that's because it is pretty subjective. What do you think would be reasonable for me to charge? It's a 2:30 minute piece.

That is a question only you can answer, unfortunately.  Pick an hourly rate for yourself and guess how long it's going to take you to write this piece, maybe.  But I wouldn't spend too much time worrying about it.  More important to get to writing this piece, and the next piece, and the next piece!  (:

That is a question only you can answer, unfortunately.  Pick an hourly rate for yourself and guess how long it's going to take you to write this piece, maybe.  But I wouldn't spend too much time worrying about it.  More important to get to writing this piece, and the next piece, and the next piece!  (:

We're discussing it now and we've agreed at 80 bucks. I was hoping for at least 100 but I can compromise a bit considering they are doing it themselves. I hope I'm not selling myself short here. Either way, thank you for the tips, I never even thought about an hourly rate. I'll do some research on that.