The copies of birth, marriage and death certificates (and don't forget this only works for about the 4 most recent generations and people need to go back 12-14 generations to the Mayflower)don't need to be expensive certified copies. Only photocopies. If you are a serious genealogist you would as a matter of course be obtaining copies of these documents for your direct line (if not for siblings of your direct line). In my case the more difficult and expensive documents to obtain were the 19th century land and court records for my upstate New York ancestors who did not have birth, marriage and death records. I hired a genealogist to do this for me because I live outside the US.