I work in a similar field. Among their staff levels, ibankers probably have an average rate about $400-$450/hour. To do a deal on the small side (like the ars deal), I would estimate roughly 250 hours. So, somewhere in the neighborhood of $100k.
Considering an analyst works about 80-100 hours a week, this deal would be done in 3 weeks. ha.
Although we're only around towards the end of the transaction, bankers are involved from the beginning. They typically get an offering memorandum together, help the company organize their financial data, contact potential buyers and do anything else necessary to facilitate a smooth transaction acting on the seller's behalf.
As far as fees go, we're by the hour, but bankers may very well get a % of the total deal. I certainly don't make ibanker money, but there wouldn't be anytime for my hacking side projects if I did!