Unanswered: Any advice for best mobile for an 11 year old?

Hi, I dont know anything about mobiles so would appreciate your opinion.

Whats the best cost effective phone choice for an 11 year old?

I'd guess it wont be used much for phone calls, but more for texts & the internet.

I saw a good review of the orange san francisco but it confused me as it was a PAYG but as I undersood it it costs