Hiring a vehicle and going on a self drive safari holiday can save you a lot of money. It does require you to do more on your holiday and you do need to be the type of person who enjoys being independent and having to make your own decisions. As far as driving in Africa, Namibia is one of the better countries.
Their road system is good and most of their roads are in good condition. Many of the dirt roads are good and are fine for most sedan cars, but in the raining season which lasts from November to April in Namibia, you really should consider hiring a 4x4 as these can get tricky.
There are a number of local car hire companies in Namibia, which many of the internationally recognised brands use anyway. My recommendation is to organise your vehicle rental before arriving in Namibia. This makes sure that there is a car waiting for you when you arrive at the airport. If possible I would also advise that you collect and drop off your car in Windhoek, as this is where most of the car hire companies are located. Renting a car form another location, especially more remote areas will often incur transport costs.
Because there is less competition than what you get in the US and Europe, hiring a car in Namibia is a little more expensive, but not excessively so. I would recommend that you shop around as there are savings and deals to be had.
Specialist vehicles like 4x4's and ones that have been kitted out especially for camping can get more expensive, but it is always worth remembering that the alternative of staying in hotels and at safari lodges will probably be far more expensive.
To help I have included a link below to the Safari Guide website that has more information as well as links to all the major car hire companies that offer services in Namibia to make it easier for you to quickly compare prices and get the cheapest car hire.
For some more information on vehicle rental in Namibia, take a look at the following external websites:
I often find that reading a good trip report to be full of valuable information, as well as full of inspiration.