If you need real cheap, get a tripod that fits the camera that you have access to along with what is called a reversing ring. What it allows you to do is mount the lens to the body backwards to get ghetto macro. For this you will want to use the standard lens that ships with most DSLR's. I have personally used one with the wife's Canon using the stock 18-55 lens. The shorter the lens focal length is set the more magnification you will get. This will be full manual though. None of the electronics in the lens will communicate with the body. However, set to 18, if I was to focus on someones eye, the only thing in the shot will be the pupil. The biggest down side to this is you will have very narrow depth of field and focusing is achieved by physically moving the entire camera. Plus shooting this way without a tripod is all but impossible.
To increase the depth of field, you will need to drastically increase the amount of light and then close the aperture down as far and you can go. I know for canon the only way to do with with mounting backwards is to set the aperture with the lens mounted correctly, hit the preview button that sets the aperture where it is set, then with that button held down, remove the lens and it will stay stepped down. It is very fiddly but can work. Though image quality will be less than a dedicated macro lens, but for borrowing camera equipment and a reversing ring only costing about $20, it can't be beat for bang for the buck.