Hello, my website offers products that we sell in mass amounts. For example, for one of our collections, the minimum amount that can be sold is in a quantity of 300, and we offer quantities of 400 and 500 as well. An example price for one portion is $1.50, but the minimum to be bought must be at least 300. How can I format the product pricing to where each product can cost $1.50 per item but will automatically do the math for the total of 300 or more items when checking out? In addition, we sell products to specific companies in mass amounts. How can we set up specific prices for specific customer groups? For example if a company wants to buy x amount of our product that we sell for 1.50, how can we exclusively allow said company to purchase x amount for the cost of $.50 instead of $1.50? However this pricing deal will only apply to said company and will vary from guest to guest. Thank you in advance.