@carlisle1 thanks, that's a good point.
So, $2.50 buys and distributes a mosquito net.
A conservative estimate, for how many nets you need to save a life comes from here:
The world's best charity can save a life for $3,337.06
http://www.businessinsider.com/the-worlds-best-charity-can-save-a-life-for-333706-and-thats-a-steal-2015-7AMF is one of only a handful of charities that meet the organization's strict criteria, says Catherine Hollander, an outreach associate at GiveWell. That means it can then be put under heavy scrutiny from the non-profit's research arm to root out how far a dollar actually goes. The final number after copious number crunching: $3,337.06.
100% of the money they get buys nets.