HOW MUCH DOES IT COST TO DESIGN A CLOTHING LINE?

To develop a single product the average cost, ranges between $3,500-$12,000+ excluding manufacturing costs. 

This depends on complexity and includes all necessary steps (Basic Consulting, sketches/techpacks, patterns, grading, samples, sized samples).

To start a successful clothing brand with  2-3 items to begin, between development, supplies, production, general business costs (registering your business, business professionals such as lawyers,accountants), websites, marketing etc.  Expect to require a minimum 25 to 50K.