E-Commerce site automation

I have a store on several websites where I buy and sell virtual game items. I want to connect a bot to a few actions on sites and automate the transactions.
the actions to be taken are:
1- Items for sale are constantly being put up for sale on the site and I want the bot to buy the newly arrived items with the mathematical ratio I have created between them within the scope of certain data on another site.
2- A target order can be placed to buy the items on the site, again in the light of a mathematical certain data, I want to put a target order on the item with a mathematical rate and also to compete at a certain rate with the prices given by other people because other people use the site because you are not the only one using the site.
3- I also sell my items on the site, because there is competition again, I want my items to compete with the items of competing sellers at a certain rate. There is more detail here Write me back so we can talk details