without a doubt the $600 i spent on vinyl and turn tables only to realize i have zero musical talent.
LOL, keep at it bro. What it comes down to is passion & patience. You can't instantly expect to be a pro in a matter of days. I taught myself so much about music, it just motivates me more to keep doing it because I used to be truely WACK. I have a much much better understanding of beatmaking than I did 4 years ago or heck even 1 year ago. I evolve the more and more I keep at it. It's just a hobby, but it certainly means something to me. You don't have to be GREAT, but just like what you do and get to the point where you feel somewhat content.
Anyways, the worst money I spent something on would have to be video games. I wasted so much fucking time on that shit in middle school and high school, I could have done better like use that time to play sports. Not that I regret it, but I could have toned it down. Shits an addiction. Thank God I don't have a PS3 or 360, I think I'm honestly done with video games. I'd rather make music if I'm going to do something that keeps my ass glued to a seat for hours.