I quite agree, but Experience doesn't have to pay for the engine overhauls!! Its a bit different being a line pilot flying through abrasive dust, or being an owner/operator watching pennies disappear along with your turbine blades and TBO extensions!
What I understood is that the Harmattan is a prevailling saharan dust that blankets the area, with low visibility and high quartz content. Web browsing reveals airports closing in extreme conditions, and NOTAMS or local knowhow cautioning against operation on bad days. It'd be good to know a bit more about it as it sounds like it might be worth delaying the deal until after the Harmattan has passed - but local knowledge would be good if there's anyone out there listening?