The costs a launch has to fund
A launch budget is not one number, it is a stack of them. The entity and trademark costs from the earlier guides land first. Samples follow, so you can hold the product before you order it. Then the first inventory run, and the freight and duties to land it. Then the listing assets that sell it, photography above all. Then the advertising that drives early velocity. Each line is separate, and each is easy to underestimate.
Budget every category before you commit to any of them. A quote for the units is only the visible cost. Freight, duties, imagery, and launch spend are just as real. A budget that covers the inventory but not the traffic leaves you with a shelf of stock. You have no way to sell it.
Fund validation before you fund scale
Treat the first order as an experiment, not a commitment. The common advice is to launch aggressively with full inventory. That assumes the product already works, and you do not know that yet. A large first order turns an unproven idea into a large loss. A small first run buys the same information for far less. It also lets you test more than one idea at a time.