$30 is most certainly not "a lot of money", and it is this attitude that makes indie development so hard these days. This app is meant for serious bloggers (i.e. those that spend many hours writing each week), so if it works for them $30 is a steal.

Remember that out of the $30 John gets just $20 from Apple, and if you take another third out for other expenses you're looking at less than $14. Needless to say you need to sell a lot of copies at that price to break even on your development time, on the order of 10,000/year, which is more than 27 copies/day! Then take into account that the App Store makes it difficult to get repeat revenue out of customers even if they use your app for several years...