Wondering about this whole able to use Sprint phone on Virgin Mobile deal

[cattc]

I cannot afford Sprint service. Plain and simple. VM offers what I need (unlimited data and messaging) at only $35 a month. While with Sprint I’d be paying close to $100 a month (no matter if no contract or contract. I currently have a Sprint number though due to being on a Fam Plan). You can see why I chose VM.

Here’s where I am so unbelievably confused:

I am buying a used deactivated Sprint iPhone 4S off eBay (buying from there because I cannot afford to buy it full price from VM). But I am wondering, can I take it to VM without having to unlock it?

I have searched and searched… and can’t find a good or informative answer anywhere. I’m pretty much desperate.

SECOND QUESTION/ POSSIBLE ALTERNATIVE: Could I buy a cheap VM phone and switch out the SIM’s between the iPhone and cheap phone? A friend suggested this. (Never done it, but they’d heard of it).

Thanks to anyone who can help me!

 

[takeshi74]

You'd only need to unlock the 4s for use with a domestic GSM carrier (i.e. not Sprint or VM).