He's probably worth $300-$500/hr if not $1k...
https://github.com/jerryscript-project/jerryscript
Granted, the targets aren't exactly the same (micro-controllers vs very small lib), but benchmark differences are impressive:
Also a lot of useless consultants would earn that much, as would people doing shady shit, as well as many talented people so the $ comparison is kind of insulting.