I'm a fan of simple tech, particularly for survival. Your proposal is reliant on 1 lighter, a working solar panel, etc. Too many points of failure and not enough redundancy. I believe in the concept of "2 is 1, and 1 is none." That means if you lose or break your only device, you are out of luck. In my experience, I have too many "batteries" that are always dead or dying (often when I need them or at inconvenient times). Laptop, nook, phone, and watches, ipod, smoke detectors, etc.
Your lighter may break or the battery fail. Your may not have enough sun to charge it, you may lose or damage the cord or charger, it may be raining or night or overcast when you need the lighter to charge, etc.
Why buy something overpriced that relies on tech when a very inexpensive low tech option(s) are available?
$23 buys a lot of disposable lighters and low tech matches. 100 matches probably takes up as much space/weight, costs pennies, and won't fail if kept dry in a small container, like a free pill bottle. Matches require zero technology (no electricity, no fuel, etc.) and can be struck on any hard surface like a rock or zipper. And several match heads can be combined for better fire starting.
For $20 you can get 3,000 matches. That's enough fire starting to light 3 matches per day for almost 3 years! Your price per daily use for 3 fires would be about 1.5 cents. Get yourself an altoids tin, glue the strike strip inside it and bingo, you've got a water proof match case.
https://www.amazon.com/Wooden-Matches-K ... tches&th=1Or for $21 you can get 50 disposable lighters. That's enough to use a lighter every week for almost a year. Your price per daily use would be about 6 cents.
https://www.amazon.com/Cigarette-Wholes ... ters&psc=1