The Authors name gets 'Top Billing' ? (my pet peeve)
Sorry, your an
unknown. J.D. Robb gets top billing. Her books sell on her Name.
You need to sell on the TITLE and cover image (at least, till you are really well known
)
Can't afford a professional Graphic artist? Try a to get a Art Major from a Local College to give it a try (and it adds to their portfolio).