The day the vendor you have bought from for so many years starts selling direct to the public, what will you do? Don't think it will happen? Remember all those wholesale nurseries that promised to only sell to Independent Garden Centers. They are now selling to the box stores, and not looking back.
The problem for the box stores? As these vendors get squeezed on costs, shipping, and everything else by the chains they will become less profitable. The market for their garden products continues to shrink. The need for much of the stuff sold is diminishing as the public continues to turn away from much of ornamental gardening. Please don't mis-undestand. There will always be people looking for these products, but not in the quantities needed to maintain the status quo as it stands today.
Business these days need to cut out as many middle-men as possible to maintain and grow profits. Who is a middle man? Lot's of box stores, garden centers, re-wholesale operations, sales people, and more. If you don't manufacturer or grow the stuff yourself, your a middleman. How can you stay viable in this environment? I hope to discuss some of the options here, but the first step is accept that businesses will very quickly realize that many wholesale operations will find dealing direct with the customer may be on way to stay viable.