Well, the UK/Australia market has lower prices because the whole reverse import thing isn't a concern.
Toradora is about half the price there as it is here via NISA:
http://www.amazon.co.uk/dp/B00KGV5NMI/
This is only true of select titles like Madoka and ToraDora, mind you. Most titles in the UK will actually end up working out a smidgen more expensive, at least upon release, because of region-specific taxes and other overheads that need to be accounted for (BBFC licensing, etc) despite the lower sales potential of the region. Admittedly, not having to dub things locally mitigates some of that, but, ultimately, the UK is kind of tiny.
This pricing is also less likely to continue in the future, as particularly for key titles, Aniplex are aware that folks in the US have started to look to UK releases, and that folks in the UK have always looked towards US ones. They've started to get increasingly involved in local pricing in ways they wouldn't previously in order to protect global pricing on their releases - Sword Art Online, for example, has a "no bundle" clause in the licensing contract, which means that Manga has to release it across the same number of volumes as the US and cannot release is in a smaller number of volumes without renegotiation. All the Anime/AnimeLTD wanted to release Kill la Kill across fewer, but more expensive, collections (two half-season sets, from what I remember), but were forced to split it across three (and apparently negotiating down from four was a challenge in itself).
I think our Monogatari releases continue to be cheaper, but even there, I gather there is increased involvement from Aniplex (and our releases are hella bare bones).
Ultimately, though, this is probably why we don't have a Madoka movie release over here at all.
That being said, we do at least have AtA/AnimeLTD pushing a middle-ground which is completely disappearing in the US. Some of the American guys I know where pretty annoyed when they noticed my UK Kill la Kill sets came with the key-art books they didn't get over there.
And here is where the game of appropriate pricing begins. If they lowered the price could they move enough units to make up for the cut they're taking from each unit moved? I think they could. As I said anime is niche in NA but I believe the exorbitant prices turn away potential customers (myself included). Take games as an example, the standard price is $60. If it was slightly lower could they move enough units to make up for the cut from each unit? Then there is the question of value, do people think lower priced games are cheaply made and not worth their time? Funimation's quality is constantly brought up because of their prices. There is also the issue of streaming, why buy expensive physical disks when I can stream the entire series? These are all questions better left to someone with a better understanding of how the market works than me.
Even before they entered the market themselves, Aniplex had years of information related to sales numbers we are not privy to, because local licensing partners are obligated to report those numbers back. They would not have entered this market lightly.
Ultimately, though, the pricing isn't entirely about selling more or making it more available in the US - it's about price protectionism. It's about maintaining the perceived value of the IP. Whilst it's a fact that they probably could sell more units in the US by reducing the cost per unit, how many sales in Japan does that cost them, and how does that effect the perceived cost of
all their anime output as a result?
(Also, bear in mind that the US push to half-season releases happened following the collapse of the value of the US dollar against the yen - whilst things where being released in singles, Japanese releases weren't actually that much more expensive than US ones. Fluctuating local currencies have a way of making things look comparatively more expensive in secondary markets than they necessarily seem in their home territories - Japanese video games, for example, look awfully expensive these days. At the start of the PS3/360 generation? Not so much. The pricetags on them haven't increased significantly, in the Yen sense, but looked at from abroad they looked insane for quite a while because our currencies plummeted (hence the whole P4A region-locking thing). Should they reduce the cost in the primary market just because the secondary markets have collapsed in worth?)