1. When the user is typing the price in the input…u run a workflow:

    and then

so u store the price individually each time the user is setting up the price in each cell’s input. U don’t store all the prices at once with a single button/action

Same thing with the dropdown. Instead picking the input…u pick the dropdown

I don’t think I understand your 3rd question. You want to apply the same value (price) to all items? If this is what you want…then instead “Make Changes to a thing” when an input value is changed…you do “Make changes to a list of things” and chose the list of things and change the field you need in ur DB Table.

I hope this helps.