I will pick any coins on the ground that has value.
Even if such a coin is worth for 0.6 cent?
Wouldn't it be wiser for you to spend your time on a part-time work or self learning instead of picking up those 0.6 cent coins?
Not likely. If someone could bend down and pick up pennies consistently all day, they could ideally make significantly above minimum wage. (very, very ideally)
Assume it takes you 3 seconds to bend down and pick up $.006 once you have a rhythm down. You'd collect $.12/minute or $7.20 per hour. This sounds crappy, but it's worth noting you'd really have no enforceable tax liability, so if you've already maxed out your EITC working a regular job for the year, this could be an exceptionally fantastic part-time job. Plus you get to pick your own hours and have no boss less Coinstar.
Sats are more difficult, though, since you'd probably want to sweep them (or organize a sendmany), which could add an extra few seconds to the process. -So now all we need is a street filled with kilosats. ETA: I guess if they're physical coins, no extra time's added since you could use the coins as-is.
ETA2: This would make for an interesting prison/labor camp. Instead of breaking rocks, just spread $50 in near-worthless coins on the ground for recess.