@Dal123:
In construction, labor rates are traditionally well documented and workflow schedules follow a strict time line, so in that context including rates is a must. Material costs and overages vary from contract to contract in construction but in artistic services like photography where so many intangibles come into play, hourly and material rates alone can't determine final cost. It's better left for discussion with the client after an appointment is made, in my opinion.
I understand as a consumer you are comparison shopping and viewing prices is convenient and a great use of the Internet - but you're not buying a widget, you're buying a creative service here based on the company's reputation. In a site like this, a cool looking gallery showing previous jobs, client feedback, and an appointment book are far more appropriate and important than prices.
I'd personally be turned off by rates being posted on a photography site, actually, it cheapens the site. So beyond the reasons already stated, something is to be said for being classy and above the fray without being snooty if the site is designed well, i.e. showing somehow that the photographer isn't selling widgets, but capturing memories.
-jim