As has already been said, you could use a macro lens or extension tubes, but I'd also like to suggest an even cheaper alternative - tho the results might not be great - a reversing ring. - You should be able to get a reversing ring for any modern dslr and lens filter size.
It is basically a camera mount on one side and a filter screw on the other. The idea is that you detach your lens, screw the ring into where the a filter normally screws in, turn the lens around and attach it to your camera. They're really cheap, but ymmv.
I took the image below in about 2011 on my old nikon d90 with a reversed 18-200 lens. It's grains of sugar on a kitchen work surface. I did it pretty much off the cuff and without the benefit of searching the internet for advice. The image is predictably poor and the depth of field was almost non-existent as you can see. I gather different lenses will produce different output, but at least it was SUPER cheap :) Oh I had to crop this to get it under the 2mb file size limit, but you get the idea
