Our 14 year old wants an Iphone for Xmas. With a limited budget, I have decided to go through Virgin as the coverage seems decent in our area (bought a cheap Android smartphone to test). Target has a 4s 16 GB for $250 as a running price but Radio Shack has a Black Friday deal, Iphone 4 8 GB for $99. Considering her age and the fact that this is her first Iphone (she is familiar with a Gen 4 8 GB Ipod touch), is the 4s really worth the additional price? Other than the GBs and siri, whats different? Thanks for any help!