Currency in Western Sahara to Moroccan dirham (MAD). For 9.9 US dollars you can get 89.7 Moroccan dirhams. For 99 US dollars you can get 897 Moroccan dirhams. And the other way: For 9.9 Moroccan dirhams you can get 1.09 US dollars.
When you're thinking about traveling and it doesn't necessarily have to be a specific country, maybe the costs will be less than in Western Sahara in one of the nearby countries? Check prices in: Mauritania, Morocco, Senegal, Mali, and The Gambia.