It's a good idea to review your prices every once in a while. Just because you have the right price now, doesn't necessarily mean it's the right price tomorrow. If you see a shift in sales, it's usually correlated to the price, e.g. if sales drop, perhaps a competitor started selling the same product at a lower price?
If you're about to start selling a product that you see other sellers are offering on Konga.com, it's not guaranteed that you need to sell it for less. Perhaps your product is high quality/has a higher sourcing cost/is of a certain brand? People recognize quality and may be willing to pay for it as long as you are clear about the benefits of your product and that it is 100 % authentic.