also your whole request is worded weirdly
like for one thing, photoshop is not by any means a requirement for making video game art, and you wouldn't even notice the difference
and another thing, knowing how to use photoshop doesn't necessarily mean you know how to draw
so what you should really be asking is if there's anyone who can make decent digital art and would like to help
aaand you should definitely be more clear about how much work it is. $10 isn't a lot of money, and "not a huge workload" is incredibly vague and not very reassuring