When I read your first post I thought, "I understand. I've got two kids and they want iPhones etc. too." They're both approaching their teenage years though. 5!? Well, when my son was 8 his best friend got an iPod touch. Couldn't believe it. What does an 8 year old do with a Touch aside from play games? (nothing is the answer, btw). I cursed the parents too because after that every kid in class wanted an iPod touch. About a month later, the iPod Touch had died. The boy thought it needed a wash, so he put it in the bath!
$300 gone. That put an end to any uncertainty for most parents.
And just look around on the web about complaints from parents about children's games that ratchet up $200 bills for ammo and the like.
So, the answer: stick with Fisher Price for the next 10 years.