Or, we might rephrase as, "No amount spent on the best tires can keep a cheap tube from giving up the ghost at the first opportunity." It is a composite structure after all, reliant upon each of it's components, each of which can be the weak link.

The issues that may exist with cheap tubes include but are not limited to poor joints at the valve stem, failures at the mold seam, inconsistant material thickness, low elasticity of the rubber.

I've also found that putting a 23c tube in 25mm-28mm tires may result in said tube being stretched a bit thin and increasing the likelihood of it flatting.