I need WooCommerce for First In / First Out functionality. The plugin will need to have "versions" for products, where a new version with a new price can be added. From the front end, the first version should be added to the cart first, then, the next version after (so the first added version's price is charged initially, then the next version's price, etc). The price is NOT averaged.
If a customer is purchasing more than the initial version's qty, the price should be (Version1Cost * qty1) + (Version2Cost * qty2) where Qty1 is the remainder of version1's quantity balance, and qty is the difference from Version1.
The Quantity available on the screen should be the sum of all versions available for that item.
I've drawn up an example that I hope helps clarify:
--------
Item A
Version001 - Qty: 4 - Cost: $7.00 - DateAdded: 2016-01-05
Version002 - Qty: 3 - Cost: $5.50 - DateAdded: 2016-02-13
Version003 - Qty: 9 - Cost: $6.00 - DateAdded: 2016-02-29
Total Qty available: 16
Purchased: 6
4 will be billed at $7.00 = $28.00
2 will be billed at $5.50 = $11.00
Total amount: $39.00
================================================