OP's question is a bit vague, so it is difficult to provide specific advice relative to your friend's business. If they sell consumer goods, are they things also sold by competitors online where you can easily check the price and shipping costs? If an industrial product, how many competitors do they have and how are the sales regions setup? Even if they sell some type of specialty product, you still need to consider who else sells the same or similar product and at what price.
Typically, I now look online to compare prices (and shipping, where applicable) when making any reasonably large purchase. Some websites appear to have a lower unit price, but the high cost of shipping makes the total about the same. Many of the home goods type websites ALL sell the same products and mostly function as a warehouse, they don't actually manufacture anything. Smart shoppers will compare prices on the various websites and if your product is always the highest price, not surprised they would be losing business.