The supplier sells a product to me at retail price less discount. This discount is as per a specific band as provided by the supplier (which your program caters for very nicely). This same retail price is what I use to sell the product to customers also at either no discount or according to discount bands. This therefore means that supplier purchase price= my retail price. Profit is therefore calculated as purchase price discount less any discount charged on my retails price. e.g. I receive 40% discount when buying and item and I sell the item for either 0% or 20% discount. How does the program cater for the above? Does this mean that the supplier purchase price I use should be the same as the retail price when I set up the stock item and I then specify the application purchase/sell?
In the stock item details, you should set the 'Our Price' input field to the retail price. Any discount will be calculated on that price. There are two ways of handling sales discounts. It depends how sophisticated your pricing is. There is a lot of on-line help on how to set up the discounts, so I won't go on at length here. But basically the whole system works on 5 levels of discount, 1 to 5. In customer account details, you can specify which discount level they receive, this can be from D1 to D5. As some customers may receive different discount to others. You can then either setup up to 5 prices on a stock item, one for each discount band (only if running the system in 'Advanced Level'), or you can associate the stock item with a Sales Discount code, and setup discounts in that code as percentages (in either Basic or Advanced Levels).
It's a very powerful system for handling discounts, it also handles markup from cost, and quantity breaks.