Make them yourself - you'll get all you need in your local hardware shop including the Melamine (veneered chipboard) - don't go to Woodies and Atlantic and the like as in my experience they are more expensive for this stuff. They are really easy to make, you can buy the melamine in different widths/colours for the shelving and buy all the rails in various lengths and cut them to size. It's labour intensive but in my experience I saved 800 euro on doing them myself over a guy who quoted me to do them. It cost me a little over 150 euro for the materials !!.
Have a go yourself.