I co-sign. Dont break the bank, just play with your camera and your kit lens. Get to know how both of them work. With time, you can see what focal length you use the most, or what you desire (wider or range) from there you can make a determination. If you find you like photography and you are actually going to stick with it and you actually like the quality (sharpness, color, contrast, bokeh, etc) then consider buying the best possible lens you can afford. It's not how you can upgrade bodies later, it's Bout the best lens regardless of body.
I had a XSI with a 85L 1.2 and till this date I use that lens without a problem.
People get so dumbfounded by knew technology that they want to upgrade bodies all the time, however the same result, mediocre pictures that they could have taken with an older body. Most of the new cameras are built for 4k and low light performance. However, if you know how to read your histogram, you should be able to get great picture regardless, only thing is new cameras are more forgivable if you under expose and want to bring up the shadows.
With that said, take everything everyone is saying with a grain of salt and make your own determination.