Hi,
I wrote $250 and 1 day because I had to fill in the fields. I don't know how many pages/words your dissertation is so, until I get this information, I cannot give you a true price and time scale. Also, I am from England so will spend extra time making sure that any adjustments I make are in American-English.
I am a qualified proofreader and editor with a lot of time on my hands.
I would love for you to email me 5 pages (to assess my ability). If you like my work then I would be happy to negotiate a very fair price for the whole of your dissertation.
Hope to hear from you soon,
Rich