Singer's solution to poverty

While Singer's idea would provide a solution to poverty, the terms of his arrangement need work. His argument is based on the idea that people should spend their income only on what is necessary, and donate the rest of it to charity. 

This plan sounds like it would work but the expense of those making the money seems too high to me. I think a more reasonable solution would be a cap on the donation amount. People would donate their excess, but only to a certain extent. That way people in poverty would receive aid, and people with more plentiful income would be able to spend their money in order to reward themselves for their work and keep the economy going.