On the best buy website, it does not say anything about a data plan requirement for a violet blackberry curve.
http://www.bestbuy.com/site/BlackBerry+-+Curve+8530+Mobile+Phone+-+Smoky+Violet+(Verizon+Wireless)/9594922.p?id=1218128969823&skuId=9594922&contract_desc=#tabbed-customerreviews
However, for a black one, it does say a data package is required.
http://www.bestbuy.com/site/BlackBerry+-+Curve+8530+Mobile+Phone+-+Black+(Verizon+Wireless)/9594879.p?id=1218128968274&skuId=9594879&contract_desc=
http://www.bestbuy.com/site/BlackBerry+-+Curve+8530+Mobile+Phone+-+Smoky+Violet+(Verizon+Wireless)/9594922.p?id=1218128969823&skuId=9594922&contract_desc=#tabbed-customerreviews
However, for a black one, it does say a data package is required.
http://www.bestbuy.com/site/BlackBerry+-+Curve+8530+Mobile+Phone+-+Black+(Verizon+Wireless)/9594879.p?id=1218128968274&skuId=9594879&contract_desc=