Think about it. If I were a seamstress that specialized in making dresses and 2 customers came in and asked me "what is a standard price for a dress?" and I reply with $500.00. I would probably get myself into trouble. For example...the first client comes in and wants a sundress for a 9 month old. It would take a day and I would make a good profit...but the client isn't going to pay that high cost. The 2nd client you quoted asks for a wedding gown. Now your in deeper trouble. Materials alone cost over $500 and you didn't even include your labor.
Due to the fact that web design is custom work its very important to have a consultation to discuss your needs to get the most accurate quote possible. Most companies like us offer free consultations and quotes. I suggest you shop around not based solely on price but portfolio and is the price worth the outcome!