Can You get by with 250 MB of Data per Month?
The iPad models that come with Wi-Fi and 3G will let users choose, on a month-by-month basis, whether to pay AT&T for 3G data service at one of two service levels. The unlimited plan is $29.99 per month, just like the iPhone's data fee; the 250 MB per month plan (combined upload and download) is just $14.99 per month. Will that suffice?
This is a good time to reset your iPhone data to see how much you use month to month.