It's often okay when building small electronic projects to use inexpensive Chinese-manufactured microprocessors and electronic components. If they go bad, especially in self-build projects, you can replace them. But you should never cheap out on power supplies, as the built in isolation of the power supplies is what keeps you safe from fire and potentially deadly shock. Good quality USB phone chargers aren't that expensive, and buying them a reputable source like a big box store is much safer then getting them over the internet.