Bad luck strikes again. I purchased my phone on my wife's line of eligibility intending on switching the lines once the phone was activated (classic buddy upgrade) but wirefly specifically doesn't allow this in their terms and conditions. They track the ESNs on the phones they sell and for the first 181 days, you can't change the line of service on the phone. I called up Sprint and they said my best option is to return the wirefly phone and then buy one at Best Buy or Sprint (online or in store).
I'm glad I caught this minor detail now and not after I had the thing in my hand. It will be easier to return a box than it would have been to have to repackage everything and say goodbye. Anyway, wirefly has free return shipping and 100% refunds for all unopened/undamaged items and after speaking with India, wirefly will reset my wife's line of credit once the receive the phone back. What a pain.
In the end, it's only going to cost me time (likely a week) and not $500 extra dollars (the penalty for violating the terms and conditions - pay full price for the phone).