I was planning to get the EVO soon as it came out and give my daughter my hero that I just got in Feb, but my daughter needs a new phone like yesterday. If I wait until I at least get a release date for the EVO then add a line and buy her a hero less than 30 days out from the release date. Would I be able to return her new Hero to get a subsidized EVO on the new line then swap phone numbers between the two so that I end up with the EVO on my number and she has my old hero on her number?