We’ve known all along that Plastic Logic’s Que, with its 8.5” x 11” form factor aimed at business users, would go for a heftier price than most of the wieless e-readers. Now we know how much more: the WiFi-only base model with 4GB runs $649, nearly $200 more than the Amazon (NSDQ: AMZN) Kindle DX; the 8 GB model with WiFi and 3G is $749.  Plastic Logic is taking preorders now for shipping in mid-April; no date yet for retail sales through Barnes & Noble (NYSE: BKS), just “later in 2010.” Holding off on B&N sales makes sense for a couple of reasons—the retailer is still on a steep learning curve with its own Nook and Plastic Logic stands a better chance of avoiding similar production and delivery issues if it keeps the sales channel narrow for now.