Im a new online Bookseller. Should I buy a pda book scanner? Is it worth the cost?

[WilsonWillington]

Im a new bookseller and I see many people at booksales scanning books with their pda scanners. I checked the price and some are selling for 500 to 600 dollars! I cant afford that.Are there any other book /dvd sellers here who use book scanners for there business. Any cheaper ones available? Thanks.