Once you have your emergency bubble inflated and your debt paid off, you can pay cash for almost anything.  This can have its up side.

I have heard of multiple discounts given simply for paying with cash Vs. a credit card or check card.  The reasoning for this is merchants have to pay a fee plus a percentage of the sale just for taking the card.  The percentages are usually pretty low but if you run tight margins it can add up.

I have heard this specifically at gas stations.  Many times, gas is very low margin only making a few cents per gallon of gas.  Now if the credit card processor is taking only a few percent, they just ate up your profits.  By offering a cash discount in between the retail price and the loss price after the fees, they can save more profits.  Pretty simple for not having to do anything!  More times than not its the mom and pop shops doing this and it will usually be prominently advertised.

Another one that can save you tons is on labor work.  This can be anything from having your roof replaced to having someone cut the lawn.  Many times, the smaller contracting firms have to put materials on credit.  If you pay cash, they may be able to negotiate a better discount if its cash your paying with.  This never hurts to ask.  A few months back, I was able to bring a roof bid down from $9800 to $9200 and get much better materials in the process.