Bently & Wilson
Pricing and services:
As of March 2012, the website lists pricing of $548 for 4-hours, $748 for 6-hours, $898 for 8-hours. There is a 2-hour photo tour available for $348 but it does have limited availability on weekends.
People who have used this vendor (sorted by date) and link to the review:
TK threads mentioning this vendor: