The thing with these is that DC created an artificial scarcity on these books. They announced covers, and solicited the books, but determined the size of the print run ahead of time due to the expense of the printing process, so they did not print enough to meet orders. They then allocated shipments to retailers because they printed short, and then filled the gap with non-3D covers they are calling first prints, but are charging the same as the 3d cover for. They are printing 4 issues of each Batman title (and others) or the month (Batman 23.1, 23.2, 23.3, and 23.4 for instance), but retailers had no idea if their customers would buy 3 extra issues in a month, and determined print runs before retailers had finished ordering. Once they announced they were allocating the books, there was a perceived scarcity for these books that started driving up the prices on pre-orders on ebay and such places. Diamond is sold out via pre-orders of the 3-D covers, retailers may not receive as many copies as they ordered, buyt the perceived scarcity is driving up demand because people are thinking ooooh these will be valuable because they are sold out, prices will skyrocket in the short term (like people paying upwards of $200 for new52 Justice League #1 the weekend it came out, but once the wave of artificially manipulated demand passes, prices will crash. You can get a first print of Justice League #1 in the $20 range now.
It's not the reality of supply and demand that feeds these frenzies, it's the perception of scarcity and availability and the demand it creates. Bleeding Cool was reporting Catwoman #23 that came out last week was sold out everywhere, and it had indeed sold out at Diamond, and it featured the one panel first appearance of the new Joker's Daughter. Prices jumped to $15 on ebay, but then BC ran a story showing retailers with stacks and stacks of these still on the shelves.
In cases like this, it is marketing manipulating people's perception of how supply, demand and prices work to artificially inflate demand, and prices will follow, as a panic pack mentality ensues. Once the panic attack passes, the true levels of supply and demand will begin to work in the long term and the true level of pricing for the book will emerge. Some people will take advantage of the short term frenzy, others will be exploited by the short term frenzy, but none of it will do anything to determine the true price of the book for the long term.