You do not need an attorney to perform a patent search, provided you know how to do it. It is a tedious task. Commercial companies like Keller Patents would charge something like $500-$1000 to perform a patent search. A complete search would typically take about 30 hours to finish. If you just want to see cursorily what is out there, start with google because it is free. Searching PTO is not easy. Although you can perform a keyword search through PTO database but normally it is not complete. You must be able to perform a class/subclass and index search. Whether that can be complete depends on how you define your search strategy. A lawyer serves its purpose.
