Looking for a buy/sell plugin, not a cart

Hi guys,
Looking for a certain type of plugin (or plugins) for another project.

This is for people who buy from the public and resell items to large companies, for example metal scappers.

Needed features:
1) Admin posts purchase prices to the front end - I have this finished

-- Never shown in frontend:
2) Admin posts purchases (expenses) and sales (income) in backend
3) Simple inventory overview
4) When a purchased item is later sold, it goes into an "archive"
5) Purchase / Sale differences (earnings) is shown based on the above content and filterable
6) Expenses such as phones, leases can be added to expenses

The input should then show monthly/yearly earnings based on the sold items and expenses.

All I need is some recommendations for free or paid plugins, WMPU or others that could make this happen.

Cheers!