Challenges of private education projects

I think that education should level the playing field (see: Correlation between pedagogical approach and science education outputs). For private education projects, it poses a challenge from the day they require to generate an income from the students themselves. If there is a transfer of money from students to institutions there'll be a filter based on income, that would keep increasing the problem of inequality.

There are different possibilities already explored:

• Projects can be built on potential future income of students, like LambdaSchool. This approach is not too dissimilar to student loans in which people incur into a financial debt to improve their intellectual position.
• It is possible to create platforms that are supported via donations, such as the case of Khan Academy. However, living off donations may not be scalable and creates a high degree of uncertainty regarding the long-term stability of projects.
• Selling products (even if Open Hardware) can generate revenue that helps sustain further development and exploration. This is the case of Backyard Brains and Foldscope
• Selling a subscription service, like Knowunity, or Coursera are easily valued at more than a billion dollars. However, their business model is based on either providing a commodity like a degree signed by a university, or it has a paywall to be used. Coursera (or EdX) have an innovative approach of offering free access and pay for the official degree.

My biggest concern is whether there is room for alternative business models that can accommodate existing patterns. For example, a combination of selling hardware and accepting donations. Is this too different from how the school-book publishing works? Editorials are for-profits, but I do imagine people donating books. On the other hand, it is also easy to imagine the lobbying for getting a book as the official one.

I wonder if there is room for state-level deals, for example providing solutions to an entire district, country, etc. Perhaps with income-parity pricing, which would essentially mean an effective wealth transfer from rich to poor (at least at a national level).