The cajon is a simple instrument in principle, basically just a wooden box. Building your own can be an enjoyable project and significantly cheaper than buying one.
If you want the satisfaction of playing an instrument you have built yourself, there are two options; build one from scratch or use pre-prepared cajon construction kit.
On the building from scratch page there is a collection of examples and guides on the internet for building all sorts of type of cajons.
Our construction kits page has details of the range of pre-prepared options that are available.