There are indicators that apps have in-app purchases but most kids and parents don't notice them.
In-app purchases require you to enter your iTunes account password so it's generally hard to accidentally buy something. The problem is that once you enter the password to make a purchase (even of a free app), you stay logged in for a while (15 minutes?). A lot of parents have been burned by downloading a free app (requiring a login), then handing their phone to their kid to entertain them for a few minutes. The kid then racks up a few in-app purchases before the login session times out. Quite a few parents learn that lesson when their kid buys a $1.99 add-on, but the really scummy apps have $99 purchases.
I generally wouldn't worry about it. If the device is for a kid, they'll probably be begging for iTunes gift cards and will learn to budget their purchases. The only real problem is when mom or dad have their iTunes account tied to their credit / debit card and don't pay attention.
In-app purchases require you to enter your iTunes account password so it's generally hard to accidentally buy something. The problem is that once you enter the password to make a purchase (even of a free app), you stay logged in for a while (15 minutes?). A lot of parents have been burned by downloading a free app (requiring a login), then handing their phone to their kid to entertain them for a few minutes. The kid then racks up a few in-app purchases before the login session times out. Quite a few parents learn that lesson when their kid buys a $1.99 add-on, but the really scummy apps have $99 purchases.
I generally wouldn't worry about it. If the device is for a kid, they'll probably be begging for iTunes gift cards and will learn to budget their purchases. The only real problem is when mom or dad have their iTunes account tied to their credit / debit card and don't pay attention.