It's at most 6 months payback for the average commute at current prices.* And that's for a $400 scooter. Think Xiaomi can't get these things into U.S. ports for $300? Think again.
Scooter share economics don't work. And now that cities are placing caps on vendors and scooter quantity, prices are going up. Which means payback period to owning the scooter goes down. This is a vale of tears.
* What is the average payback period for purchasing a car (μ(p) = $30,000) versus taking the train? Much longer!