Your arguments are against providing exact pricing, that are rather obvious. The discussion seems to be about ballpark estimates. I'm not sure how to display this, but something along the lines seems reasonable: "Moderate installation at local high-school should fall under 1M, while a state University might get basic feature-set for 10M". Large enterprises have whole departments for price-bargaining, but the smaller ones and especially public ones want to know the ballpark before issuing an RFP