You know. I saw this thread a while ago. Unless I can think of a way to add value… I tend to just follow it and not comment.
After some thought… my answer is never. I have never had a cheap component that sounded great, I have had cost effective… or good budget components. But, the only components that have blown my socks off have been incredibly well thought out and constructed audiophile equipment. Not one “cheap” component that I can think of ever sounded great. I have owned at least a hundred components. I would imagine after over fifty years of pursuing the high end for my main system, portable speaker system (I spent over ten years living in motels), portable headphone systems (I spent over 40 years while traveling and listening (pursuing the best possible sound), permanent headphone system (20 years pursuing the best), and permanent office system.
While looking for bargains is great. The way to get a truely great audio system is not to look for cheap stuff. You just get cheap stuff… and it might at best sound OK.
Great sound comes from dedicated companies willing to invest in research and development, quality components, and outstanding manufacturing quality.