Cheap vs Expensive Writer. Which one work best for you?

One never knows, really. But certainly one can be buying stolen property, yes.

Most of the time, it's not really comparing like with like, looking at the output of cheap and expensive writers.

People buying $5 articles are often (I won't say "always") using the word "article" with a different meaning, and are buying it for a completely different purpose, from people buying $25/$50 articles. Many customers paying $5 (or less!) for an article are actually buying what some of us would call simply "A chunk of keyword-optimized text which will pass Copyscape and to which backlinks can be attached"; in other words, they're written for search engines rather than to attract human readers. This is, of course, typical of the SEO approach to what some people imagine is "article marketing" (but isn't really).

From the writer's perspective, these are generally bad clients to have. Typically their own businesses don't survive for the long term. These are, therefore, writers many of whom have to replace their own clients continually.

This is the main reason you see writers who create $5 articles continually advertising. You don't see so many writers of $25/$50 articles advertising for clients, not because there aren't any (as some wrongly imagine) but because they're often fully booked by regularly returning clients who know how to use the articles more successfully and productively, with the common outcome that their own businesses do survive.

Of course, I don't suggest that the "two sorts of articles" are typically the same quality, at all.