The biggest component of the cost of crowdfunding is marketing. On average, you spend from 2 to 10 percent of the expected proceeds on marketing. For example, if you are going to fundraise 3 million you need to spend from 60 to 300 thousand dollars on the marketing alone, which is quite a significant upfront investment.
The beauty of such a campaign is that you actually don’t need all of that money upfront. You only need some initial upfront capital, and then you can cover the cost of marketing from the ongoing proceeds. For example, you can invest initially 15k to raise 150k, and then spend those 150k to collect 1.5 million. In such a case, your goal is to generate from the business or fundraise from friends and family the initial “development capital”, which is the money you need to put into tech, legal, and marketing to set up your campaign