Indeed, as the trio left there were several people and beasts keeping an eye on them. Those that were watching him, just waiting for an opportunity to kill him. There were also those that sold information that were watching his every move and compiling a list of his movements. Which they would then sell to the highest bidders amongst the information gathering and selling organizations.
It was indeed a very lucrative job, but the money that you could make had everything to do with the rank, how dangerous, how elusive and how sought after the information about that particular individual or group was. The more dangerous and elusive whoever you were following the more money the information that you gathered would be worth. If it was someone of particular interest to numerous organizations, factions, groups and individuals, like Havok you would get top dollar.