How can we automatically calculate a sales price from a purchase price?
I believe there is no such standard functionality for calculating SP based on purchase price. You may have to customize it.
Well probably not strictly true - on a the item record you have the sell tab and the price update which you could base on controbution ratio and the basis being the purchase price, which meant if you also updated this it may work. Not something I have played with. You also have the costing version which for manufactured items can suggest a sales price which in turn could be based upon a cost price method of calculation group, which itself could be set to look at the item purchase price. This would then look at all purchase prices throughout the different calculation groups applying the uplift percentages. Generate the price and then it appears on teh sales orders. You can also run this calculation from teh sales lines and transfer it to the order.
However you are probably correct Pranav and the requirement is much simpler than the steps AX allows you to do it.