What do I need to get started as an electronic musician?

I’m tired of talking the talk. This summer, I’m on a break from grad school and I’m working only part-time. Hence, I’ve got some time I plan to devote to making music.

I’ve got a background in percussion and guitar, although the music I would like to begin to (learn how to) create is electronica/house/techno/misc. beat-making.

I imagine a computer program (Ableton, e.g.) would be a good place to start. I also was thinking of buying a synth or a keyboard. Additionally, I was thinking about one of those drum machines. Does a computer program usurp all of these? What are the chances I can Dj with these as well? Should I go with an Akai APC?

Generally, I want to be able to create my own stuff be it on the keyboard or a beat, and then mix therein, with vocals or whathaveyou. I want to have some fun…

I’d be willing to spend a little dough, but I’d prefer to keep it under $500. I know these are slippery slopes.

Again, however, as you can see/read, I am not sure where to begin. Help – any and all info will be very useful! :)

Thank you…