NEW YORK: Research In Motion says its tablet computer, the BlackBerry PlayBook, will start selling in the US and Canada on April 19 for $499 to $699.RIM said customers can start pre-ordering the gadgets — its answer to Apple’s popular iPad devices — through consumer electronics retailer Best Buy.The PlayBook has a 17.5-centimeter screen, smaller than the iPad.It runs BlackBerry software and can connect to a phone, acting as a bigger screen for it. RIM calls it the first “professional-grade tablet.â€The iPad 2, which went on sale earlier this month, also starts at $499.The $499 PlayBook comes with 16 gigabytes of memory. For $599, you get 32 gigabytes and for $699, 64 gigabytes.RIM reports fiscal fourth-quarter earnings Thursday.