iphone questions????

[Jamie V]

ok so i have blackberry curve with sprint and im wanting an iphone so i wanna know if it is a good idea to switch to att .we currently have a sprint Everything Data Share 1500 plan is it a wise to go to att. and my other question is . is the iphone 3gs better than the old iphone? what are the differences if its just that it has a video camera then im not waisting money on the newer one. and finally how much would it be a month for a basic plan with unlimited texting