We often get guys come in and ask for quotes on 100's or 1000's of items and then they say "Ok , i'll take 10 now"
When you tell em that 10 will cost 5x the price of 100 , they invariably winge and moan and promise they will be ordering the 100.
We tell em this: "when you place the balance of the huge order , we will credit you the difference between the 10 price and the 100 price"
There is no argument against that , if they pay and never place the big order , you get a fair price. If they pay and place the balance , you all get a fair price , if they walk out in a huff , they were bulldusting you in the first place and thats a bad start to any business relationship........