High end bodies usually have larger camera sensors, faster speeds, and other superior features. A good lens will produce an amazing image if used right. But what is more important to have?The answer is always the lens. While it is nice to have a high end body, having a nice lens is more important to produce better images. Always remember that even though the camera body processes the picture; Everything must pass through the lens.
Not only is a lens a good investment from the standpoint of image quality, but it is a smart move financially. A camera body that cost a thousand dollars 10 years ago, may cost less than one hundred now. Like all technologies, when the next thing comes along the previous generation looses value.
A lens on the other hand will maintain, and possibly gain value. A lens made 30 years ago will work just as well, if not better than a new lens. Over the years I have gone through three camera bodies, but the lenses remain the same.
While we would all like to have a high end lens and a high end body, we cannot all afford it. A high end body will need to be replaced every few years to remain on top, a good lens if cared for, will remain superb for generations.