If I buy an iPhone on Sprint can I transfer it to Virgin Mobile?

I want to get an iPhone on Virgin Mobile's plan, but I don't want to spend $650 to get the phone unlocked. If I get an iPhone on Sprint or if I buy a used iPhone, can I move it onto Virgin Mobile?
I currently have a phone number that I need to keep, and I'm currently using Republic Wireless as my service provider.

You mgiht

Go to second, third line on the following web:

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just copy past in other browzer

No you can't.