What is usually left out of a low lingerie quote?

The costs easiest to leave out are testing (colourfastness, fibre composition, OEKO-TEX 100), packaging (polybag, hangtag, carton), third-party inspection, pattern and grading development, and inland freight to the port. Each of those is a real cost that has to land somewhere, either in the unit price now or in a supplement later.

Ask for the quote in writing with the exclusions listed. A factory that will not list them is not cheaper, it is quoting less product.