Can I buy a cheap prepaid phone, and switch it for an enV?

I've been looking at phones online and I really want an enV2, but I need a prepaid phone because I don't want to pay for minutes I don't use. So here is what I am thinking of doing. I will buy the cheapest prepaid phone that Verizon has and activate it. Then I will buy an enV2 off ebay, log into my account on Verizon's website, enter the esn of my enV2, and have it activated to my account. I will probably sell the cheap phone afterwards. Will this work? Has anyone tried this or something similar? Thanks for any help!