If I activate the "U.S. Unlimited Text" add-on for 3 days (by texting 3TXT to 4545), what will I be charged for any data that I use? $5 per 50MB as stated in the "nitty gritty", or is that just for the "U.S. Data with Unlimited Minutes & Text" add-on? If the answer to my question is NOT per 50MB: - I'd like to know what the overage charges are. - The "nitty gritty" should clarify what add-on it refers to.