Earlier quoted context omitted.
how does one find business ideas that you can charge 300/customer? is it 300 per month or per year?
Any B2B idea should run 300/mo easily. Finding those businesses to sell to is the challenge. But perhaps it's easier selling 300/mo to X businesses than selling to 5/mo to 60X consumers? You decide.
B2C products live and die by viral growth and word-of-mouth, because margins are not usually enough to support a consultative sales process or any sort of intensive advertising. That requires a founder that's really good at reading the zeitgeist and identifying needs that customers never knew they had, and that understands human psychology on an unconscious level. Often technical skills (on the founding team) matter more for B2C markets as well, because it's more critical to stand out from the competition.
Timing also matters more with B2C. There are some time periods (now, dot-com bust, or the late 80s & early 90s) where there are basically no viable B2C ideas available. There are also time periods (early 80s, dot-com boom, 2009-2013) where they are abundant. Unfortunately you often don't realize this until hindsight reveals all the people who kept working on their B2C ideas throughout the bust.