When you spend weeks or months shopping from shops or markets around your place, you will have known the perfect seller for you. You will always have a favorite shop that sometimes you would postpone buying an item when you find the shop is closed. There is a shopkeeper at my estate who is now friends with my parents. We can take goods from him on credit and pay later because he trusts us and we trust him. We could go to other shops once in a while but his shop was our favorite. Do you have a favorite market or shop and what do you benefit from depending on one supplier?
It depends on the supplier you are buying goods from. Some suppliers give good discounts and sales leads to repeat customers while others enter into a comfort zone and may short change you with inferior products. So, in the end, it will depend on the personality you are dealing with but in most cases, it pays in terms of savings.
I am of the opinion that we should have various choices when the case of buying things that we need are concerned. In as much as I think that having one seller is good, there is need for me to always check out for changes in prices so as to be able to have the best deal when purchasing new products.