I think what the article is trying to say is "Buy the best quality that you can afford". Unfortunately the Author has completely conflated Quality with Price.
The main point - rule of thumb - that can be derived:
consider removing price as the default decision criteria
Most of the comments here (and parts of the original article) are elaborations on applying this principal. So price is not necessarily correlated with quality, but using price as a default decision criteria results in suboptimal outcomes (stuff that is not really "better" or consumers that are happier or otherwise benefited).
Higher price != Better Quality (not always anyway)