I think it comes down to who is the most easy to replace. If the sellers kind of have a big chunk of the market, and can choose between vendors, you're indeed

I think it comes down to who is the most easy to replace. If the sellers kind of have a big chunk of the market, and can choose between vendors, you're indeed in a difficult spot. On the other hand, if the market has multiple sellers, and you offer a unique technology, I wouldn't worry too much.