Ask HN: How to answer if somebody asks how easy it is to replicate my startup?

I'm building startup and I already have some traction and it really helps and solves users problems. It is not that difficult to build type of startup that I built. Sometimes people ask how easy it is to replicate my idea, what if somebody build exactly same product and offer for lower price, what is stopping others to build the same product you built. Honestly, for me it is difficult to answer this questions, because I know how easy it is to build. How would you answer to this type of question assuming you have a startup/product?