I know there are those who do not agree… but in my opinion, the single supplier “best price” story is a con job. Get a second supplier and compare prices. The reps are under the gun to produce the best margin possible for each account they sell to and you being a sole source customer does not change this.
Having seen the margin performance list for the customers in our town from one vendor, I can tell you absolutly, that the sole source customers were NOT at the low end of the margin scale! The district manager showed me the list when he was complaining that they did not make enough margin on my business due to my price shopping. He actually stopped talking and laughed out loud at that point and stated that he realized how silly that sounded and that it was not my problem. We parted with the understanding that I would buy the products they could supply with the best prices and that I would reduce my orders to once per week where possible to help them save delivery/order handling costs. Since that time, they have come up products that we now buy from them by working with the brokers to get better pricing and we are both happy.
There are a lot of moving parts in the pricing of the things we buy. Pepperoni comes from a manfacurer, through a broker to the distributor before it comes to you. Each of those entities can change the price. There is a good chance the same pepperoni is available from more than one distributor and if, not another one just as good can be purchased. Tell them to sharpen the pencil!
If the vendor is providing you an extra service that is worth paying more for, so be it… but being nice to me, delivering what I order and solving the occasional problem is not an EXTRA service… it is just the bare minumum.
Yes, there will be a handful of items that you can not duplicate or replace, but they are surprisingly few. After all, onions are onions.
One of the keys to doing this is that you have to watch the prices every week. Just stay professional about it. Explain that your interests as a business person are to do as well as possible on your costs and that if a vendor has your best interests in mind (they LOVE to talk about partnership don’t they?) that they will help you do this.