Chazz- the new figures in the smaller carded bubble are what are being referred to as "Trilogy Figures"; they are basically repacks of the Fellowship and Two Towers figures. They are also releasing the last two waves of the ROTK figures on these cards, which is why Pip in armor, King Aragorn, etc are in the new bubble style. The Trilogy Line are pretty much rehashes with a few randoms in there, like boromir and Arwen, which are single carded. The figures that had bases and diroamas don't have them now as they are just the basic figures. This is a way that TB is letting newer collectors to the line catch up and since they knew ROTK was going to be HUGE, they prolly figured might as well release the entire series of LOTR figures!
As for prices, the ROTK figures in the big bubble are in the bigger bubble, which probably cost more production wise, which is why they have to charge that extra buck or so. Hope this helps!