Buy depending on your budget and requirements then forget everything else. Easy to say but difficult to adhere to.
Just make sure you've got enough budget for your type of shooting. That said, here's a list of all possible expenses. Please ignore if you already know about them. I've listed them because it's just not the body anyway that's important.
1. Lens (UWA, Wide, Macro, Portraits, Tele). I need all of them...
2. Lighting equipment (minimum requirement: 1 flash). I've got 2 bags full of it... - 2 flash, 1 LED, reflectors, umbrella, stands, etc... I'm using beginner strobist stuffs.
3. Filters (Polarizers, UV, GND, ND, Reverse GND). Again, I have all of them because I'm shooting landscape also as my past time.
4. Camera body. This is the last but important requirement. Depending if you shoot sports, landscapes, macro, portraits, choose your camera body. e.g., 5D3 may be better in IQ than 1DIV but definitely, 1DIV or 1D3 are better than 5D3 for sports or birding given enough light. 6D might be better for low light static photography.
That said, I'm still using 500D (planning to upgrade to a 6D body later) for hobby and a 5D2 for official things (events shooting, hopefully my boss upgrade it to 5D3. He said I don't need it.