See if you can negotiate reselling the imagery they sell you. It might be hard to get agreement with this as the vendor will have you both as a customer and compeditor but if you pull it off, you could recoup your costs and then some. For a few weeks, no one else in the private sector will have the freshness and/or quality of imagery you do.

> The jets/balloon angle is interesting

Maybe I'm missing something obvious, but what about drones? Probably would have to get permits most likely, but still might be cheaper than alternatives (although balloons are hard to beat when it comes to costs, not always reusable though).