How to quartile based on multiple items and bids

Hi. I am wanting to get the 1st and 3rd quartile from a column that has hundreds of unique names.

Column A has the Item ID, Column B has the Bidder ID, Column C has the price that was placed by each bidder.

There will be will around 50 bidders and a couple hundred items, so I want to have one formula that I can use in Column D for the 1st quartile and another in Column E for the 3rd quartile. The formula will look at each item and it's corresponding bids and return the 1st and 3rd quartile for only the bids that were submitted for each item.

Once I have this information returned I will be able to identify any outliers, proceed to identifying the best bid on each item, assign a letter grade to each bid, and provide feedback to the bidder as to how their bid compared to everyone else.

Thanks!