Solar flashlight design for 3 rd use



Looking to design a tough, inexpensive ($20) solar powered flashlight/ lamp for some projects in Africa/Haiti. Lite-Bright recommended a XM-L emitter. (Thanks B-L) But it is too expensive. Is there a good balance between the top of the line and generic 10 lumens LEDs? I need: low cost, a total of 100 lumens, efficient to the max to use a small solar panel (.40 watts), along with 4 to 6 Lithium AA generic rechargeable batteries. Any ideas? We are talking mass production, nighttime study/cooking lights, for dirt floor homes in 95 degree heat.