purchasing a 7750 on ebay

[runningphan]

i'm in the market to purchase a 7750 and am currently with sprint. i do not wish to use both a phone and bb so the 7750 model is a great option for me. the only problem is it is pretty spendy, but i've found some available on ebay for a manageable price. here's my question....all of the available used units say that they are for verizon. i'm sure that the units were used on a verizon account. can i buy one of these and have it work on a sprint account? blackberry reps told me that the units are the same but i'm wondering if you can switch the network provider.

thanks, i'm loving the possibilities of the bb.....