Prime members only. Amazon with henyayatoy has the SYMA S107H-E RC Helicopter w/ Built-In Battery on sale for $39 (Prime price) - $19 off with coupon code N5NYAFZR at checkout = $20 with free shipping. Good beginner option for kids. 

• Charges in 60 minutes, has a flight time up to 10 minutes. 
• For use indoors only. Flight altitude up to 32 feet.