iphone 3g s
Yes, depending on the network you are signed up to. You need upgrade status to get the new iPhone, again, that also depends on the network you are signed up to.
The IPhone 4's from Verizon are the same as the IPhone 4's from AT&T. The only difference is the service.
iPhone 3GS
iPhone 3G S = iPhone 3G + Extra's
200-300$, Depends.
The S stands for Siri, she is the intelligence assistant created to help iPhone users.
Selena Gomez Has The iPhone 3G [s] =]
The iPhone 5 has already come out.
iPhone 6s plus
Both the iPhone 3G and the iPhone 3G S support MMS with the 3.0 update.
No, the only phone with higher quality is the iPhone 3G[S], and the new iPhone that isn't out for you yet.