Even with zero late payment fees, pay Credit Card to buy appliances or pay for something is already paid certain premium compared with pay by Cash. Almost for all home appliances, you can find and order them in neighborhood shop and pay by Cash with certain discounts.
If you can settle a wedding diner with full Cash and getting a discount, the saving is far more then Credit Card rebate.
Did you try and compare? I have done 2 reno over the past 8 years and have done a lot of comparison between stores. In general, neighbourhood shops does not give a better price. You see those big stores listed price is chop carrot price, you need to ask and bargain down. From my experience, they can usually go down to a lower price which neighbourhood store cannot match. If you don't want to bargain then neighbourhood shops might quote a lower price.