1st of all, you gotta understand beats.....so download fruityloops and get that shit poppin.
Then, you gotta know what reverbs/effects to use....ask people on here, they might know some good plugins for Logic/Cubase/Buzz that you could throw on the tracks.
Last but not least.....once you understand EVERYTHING....cop yourself the keyboard.......But if you dont understand how to setup the beats before you get the keyboard, you're fucked...and your keyboard is gonna collect dust......
if you insist on getting the keyboard, try to get a triton, and get it on a payment plan......if its like 80$ a month, and you can drop 1000 on it, you'll have another year to come up with more cash on it, ya dig?