Please don't ever use age as an excuse. I am 15 and I run three websites, handle my Paypal and checking account, conduct business on my sites, and sell good on eBay without a problem. Also, please don't ever user money as an excuse. If you received $150 from Skylight and spent it so quickly, it shouldn't be his fault. Especially if you were being dishonest.
I think you should do the right thing. I'm sure people would start trusting you if you could pay back Skylight some or all of the money. If you don't have any, ask your parents. If they won't give you any, sell stuff on eBay. If you justify things now, you'll save $50 by keeping a good name for yourself on DNF.
It bothers me when people are dishonest in any sort of business.