Why? They are both retail items and the price is negotiable if you ask.
Maybe, but do you go into an auto parts store and say, "I need those break drums but I want them for 15% less."? Not around my neck of the woods, you don't anyway.
Here's an example, I needed some DOM (drawn over mandrel) to make fittings for my QA. I called the metal dealer in the nearest city whose prices are much higher than the net guy or the guy who owned his place before him, even with shipping. I figured if he had it and the price was reasonably close I'd get it. He said I can order it for you and I said, "thanks but I'll look around." I figure for his high prices I'll go elsewhere but I never asked what's the discount, cause he'd say, "None!". Fine, I think he should ask what he wants and I shoud decide to pay it or not.
The same with Deere parts, if the guy is just scalping you, go elsewhere but if he's about right than let him make his money. Either way it's your option to buy or not. Expecting a discount gets you nowhere. He wants what he wants and you pay what you're willing to pay. If he's 20% higher than everyone else and you get the same service, he'll be gone because people aren't stupid, well most people anyway.
Goes back to what I said earlier, "make your money but don't screw me." He's got to make a living and you have to exist too.
I don't expect anything, if you treat me right I'll keep buying if you screw me you'll be asking yourself, "whatever happened to that good customer?"
The customer is the guy with the power because if he decides to say goodbye your business shuts its doors. Smart dealers know this and know how to treat good customers.
Rob