the hardware i mentioned above are quiet old so they shouldnt cost alot. just start with a simple yamaha keyboard, wich has midi out and some saving slots. buy a mixer, either a soft or a hard one. its vital that you know how to play keyboard. so if you cant then you should start taking lesson. its vital.
hmm.. when you get the hang of it, buy what you think you need most, synths, drummachine, mixers etc. depends on what kind of music want to produce or you just want to remix.
btw if you are going for software, go for "reason"by propellerheads. and please support the creators by buying it rather then downloading it.
good luck, if you need help just pm me.