They cost <$500 at retail prices. Assuming they have 15 miles of range at max speed (15mph), worst case one charge only gets them $10 ($1 to start + 0.15/min * 60min), $5 of which goes to the person who picks it up and recharges it. That's 100 cycles to breakeven on worse case (one person rides one scooter until it dies).

They've disclosed that an average scooter does 5.5 trips/day ($5.50), assuming everyone rides at max speed nonstop, that still ~$14.50/day. Pays for itself in under 2 months.