I've been working in the CMS arena for 10 years, and the whole time I've been expecting one or more “industry standard” CMS's to come along, but instead we've seen thousands of competing products with almost every web agency claiming to have CMS product.

While development costs have come down a long way due to greater experience and code re-use they still haven't come down anywhere close to the level that people are used to from purchasing shrink-wrapped mass market software.