You should know that most people travel to Namibia by land, and not by air.
The fact is that there are not many international airlines flying to Namibia, hence ticket prices are not that cheap. Depending on how in advance you buy the ticket, it may cost you between 800 to 1,300 euros per return flight between say Germany and Namibia.
If you want an alternative in flying to Windhoek and drive to the coast, we’d recommend flying to Cape Town and go up the coast all the way to Namibia. This option will be more flexible offering plenty more flights and thus cheaper.
Air Namibia, the Namibian flagship carrier, operates flights from Frankfurt, Cape Town, Johannesburg, Victoria Falls and Maun to the Windhoek’s International Airport.
There’s another option which is not cheaper though. The flights between Eros Airport, a smaller airport and Cape Town is also an option.
If you're flying in from Europe then flights from Frankfurt, with Lufthansa, will be your best option.
Other airlines that often offer flights: