Bat control is highly specialized work, and it also varies a great deal. Some jobs are simpler: such as a small colony of bats in a well-maintained residential home. Some jobs are very complex: such as a very large colony of bats in a large building in a state of disrepair. All bat jobs require a perfect exclusion coupled with 100% sealing of auxiliary bat entry/exit points, and then professional bat guano cleanup.
It's impossible to list prices here, because of how much bat projects vary. However, if you give me a phone call, I can start to get an idea of the scope of your bat project, and give you an idea over the phone. An actual detailed site inspection tells me the info I need to know, and I will give an exact written price quote at that time.
Can you do the work yourself for free? With bat control, certainly not. Bat removal is the most complex of wildlife removal jobs, and subject to several state and federal laws. Someone without extensive experience will not be able to do the job correctly, and might kill or injure some bats in the process.