Prostock is made for the actual player, where retail is mass produce in a curve which is usually not used by the actual player. In this instance the "Retail" Kovalev is a heel wedge and his "prostock" curve is a toe curve. His new Warrior blades aren't the same as his older Inno blades I've seen either. He's switched to the checkerboard pattern.
As for the original question. Call HockeyandSkateoutlet, they have them on occasion. If they aren't instock, as if they know when they may get another shipment. Also the Habs equipment sale is tomorrow apperantly. Try and contact someone in the area (maybe on the Habs forum) and get'em to pick you up whatever you can find.