20 pts for fashion questions

Why is defining the parameters of the project the first step?

What is the difference between the cost of production and the retail cost?

Give an example of when a very expensive, specially made button would be a need instead of a want.

(By parameters I'm assuming you mean the material measurements) Setting parameters beforehand is crucial because this sets a limit to how much material can be used, hence potentially affecting the cost, quality, size, and production/production rate of the product.

Production cost is how much it costs to make/produce something, while retail cost is the price being demanded for the finished product (how much it cost to make this dress vs. value of how much we want to sell it for)

In certain circumstances, a high-end button would actually be necessary because the rest of the garment/product may be either unique/specially made and requires costom buttons, or the rest of the item is just very high-end, in which it would not be fitting to use a button of lesser quality. (example: you're not going to wear cheap flip-flops with your MK dress and Steve Maden purse)