I see many companies and clients jumping on the "developing an IPhone Application bandwagon". Its definitely a hot medium for delivering your web application, content, products and services to.
One big disconnect I see is that many companies don't even have a mobile friendly version of their web site or application yet.
Enabling your customers and users to be able to get at your companies information, products, services and other important offerings through the standard mobile browsers and screen resolutions seems like a great start.
Applications average about 15-35K in my experience. This is for very basic applications. This is because of the specialized nature of the programming skills involved.
An IPhone application would service only the IPhone market and not the upcoming Android
or Windows Mobile market.
Seems like it would be wiser to spend 2-5K and create a mobile version of your web site as a starting point, get your feet wet in the mobile browsing market before you commit to mobile application development. Not to mention you could target the popular IPad market as well with your mobile web site.