Apple stores have lines for the 8-inch screen version of its trend-setting iPad. But anecdotal reports indicate that opening weekend sales will fall far short of the pace set by the company’s other recent products. That’s contributed to a 3.4% decline in Apple’s share price today, to $576 in mid-afternoon trading. The price is off 4.5% from about two weeks ago when CEO Tim Cook unveiled his long-awaited challenger to 7-inch screen tablets from Amazon, Google, and Barnes & Noble. Critics say that the iPad Mini, with its $329 entry price, is too expensive to knock out its less costly rivals — which also offer sharper screen images. Piper Jaffray analyst Gene Munster projected that Apple could sell as many as 1.5M units of the new tablet this weekend — about half the number of new iPads Apple moved the weekend in March when they were introduced. But Sterne Agee’s Shaw Wu remains optimistic. “We believe what a lot of critics miss is that [Apple’s] products are still by far the easiest and funnest to use with price points that most find reasonable. We believe this has been instrumental in helping driving greater than expected sales each time.”