Why minimums exist
Every new style has fixed costs: making the pattern, grading sizes, setting up a production line, buying fabric and trims. Spread over a few pieces, those costs make each garment expensive; spread over more, they shrink. A minimum is the point where the economics work for the factory.
Fabric is often the real constraint. Mills sell fabric in minimum lengths, and custom colours need a minimum dye lot. If you can use a stock fabric, the minimum can usually come down.
How minimums are counted
Most clothing minimums are counted per style and per colour, then split across your size ratio. Always ask whether a number is per style, per colour or per size, because the difference is large.
How to start small
Use stock or available fabrics, keep colourways to one or two, and limit custom trims. Then re-order the styles that sell. A supplier that is set up for flexible quantities will help you plan this from the first conversation.