Update: My discussion here is somewhat flawed. I became fixated on the idea that the iWork apps are now very cheap after seeing the UK prices. So, yes, for in the UK iWork is now much cheaper so I think my points stand. However, iWork has always been priced lower in the (larger) US market so there isn't really much interesting about the App Store pricing.
The pricing of the iWork applications for Mac has two key effects. Firstly, like with all apps, the price will go a long way towards determining the volume of sales. Secondly, the iWork apps will set an expected price for well designed and powerful productivity applications on the Mac. Similar to on the iPad, I expect the iWork apps will have a prolonged showing at the top of the charts. Everyone who uses the Mac App Store is going to see these apps, and their price.
The iWork applications for Mac cost £12 in the UK App Store. This totals £36 for all three: half the price of the boxed suite (£72) which is still available from the Apple Online Store. (Interestingly, the US price is reduced from $80 to $20×3 — a reduction of 25%. Apple’s sterling exchange rate outside of iTunes and the App Stores is crazy.)
My initial reaction to this pricing was disappointment. From the perspective of someone who likes to pay for quality and likely a future software developer, this slash in price seemed too much. I don’t want a flood of cheap, poor applications. Apple is underpricing such high calibre tools, and smaller developers trying to making similar quality apps will suffer.
However, I've already said how I expect the iWork apps to stay at the top of the charts. The low prices will guarantee this. This is fantastic for the documents/presentation software market — a very important subset of the productivity applications market.
I believe that far too many Mac users use Microsoft Office, when it really isn't the right tool them, and iWork (particularly Pages) would suit most people better. Apple is forcing a more balanced market — possibly at the expense of revenue.
Aside: Update Pricing
In the past, there has been no upgrade pricing for iWork. In fact, there is a discount when buying iWork with a new Mac so you can end up paying more for an update than the first version. Standard App Store updates are free. I am interested in what Apple will do here: will it be free to upgrade to iWork ’11 (or’12) — a major change in strategy for iWork — or will we pay again. The best possible solution, from my point of view, would be for Apple to build a paid updates facility into the App Stores.