Questions about Epson Ds-6500

Our DS-6500 (bought in 2015) only has USB. The manual says something about an optional network module, but I don't know if this is available to buy. The DS-6500N has a built-in Ethernet connection, but is also 50% more expensive, which in my opinion is overpaying.

You can check the delivery date on the following page under Availability by entering your email address and clicking "Send request": Epson DS-6500