In case are not familiar, devices like this were popular many years ago (1950s-1960s-1970s-etc.). Instead of using batteries, they have a solenoid charging system (you expose their backs, which have what look like glass beads, to the sun for an extended period, and those charge the device. 

If you don't have experience with one of these devices and are contemplating buying one, I would suggest that you first check out a YouTube video on how to make use of one; Using Weston Exposure Meters by Peter Elgar is particularly informative. 

To be completely honest, in my own personal, non-professional option, these devices were never terribly easy to use. I think they went by the wayside when cameras got more high-tech and built-in systems to measure and account for lighting when taking photos. 

So, who would want one of these things today? 

My thought would be an older, veteran photographer who liked doing things the old way, when photography was a craft and not just a PhD (push here, dummy) point and shoot system. Or, maybe someone who just appreciates vintage things in general. I feel like I have priced this item very competitively. 

Thanks for looking. Happy to answer any questions, if I can.