how to check the authenticity of apple ipod?

Hi everone,
I am bidding on a 20 apple ipod video lot and the price is super super cheap, but the seller accept escrow. Can anyone tell me how to check if they are 100% authentic? the only way i can think of is open all 20 boxes and check the serial #. Sorry if this is a silly question. Thanks all.

Please follow these steps to check the authenticity of any supplier...

1. Call the telephone and fax numbers provided to ensure they are real and current.
2. Check with the registrar of business of their country the supplier is located in the mentioned country. It will help you to verify that the business is legitimate and licensed to operate.
3. Pay for a sample before any bulk purchase to ensure that the item meets your specifications and expectations.
4. We highly recommend you to please do not use any other payment mode except Credit Card,Cash on Delivery (COD),Letter of Credit (LC),Escrow.com and Paypal.

salehoo reply is always not so much useful...

I dont know how you can check if they are authentic but where are the serail numbers located on the iPods.