Focus on the key skills that are going to make you a good filmmaker and story teller. TBH you can learn all that with yout camera phone. But if you're determined to buy a new camera then I can tell you from personal experience that the GH4 is a brilliant bit of kit. But if you can cut corners by getting a second hand GH3 etc. then it leaves you other cash for SDs, tripods, external mic and so on.