Calculate "Average Order Value" on an Auction Website

We are conducting this project as part of our business plan to find 'Average Order Value' on a competitor's website. This job doesn't require any serious mathematical skills as the calculations are quite simple - all it requires is time.

The subject is a courier auction website and the URL will be disclosed upon bid acceptance. For the sake of your understanding, please follow this URL of a similar website: http://tinyurl.com/2cmnyzs.

The winning bidder will need to read the listings for the past 12 months and calculate the "Average Bid Price Per Item" by adding all bids on an item and dividing them by the number of bids on the item.  The "Average Order Value" can then be calculated by adding all previous readings divided by number of readings.

We will also need the percentage breakdown of categories the items have been listed in (main categories only, no need for sub-categories). For example: Vehicles - 40% of all items, Household - 26% of all items etc.  

And finally the percentage of eBay related items on the website (we'll explain what it means in detail).

Job to be completed within 2 weeks.

Any questions, please feel free to PM me.

Thanks for reading.