Revel is kind of a special case as they are by Harmon, who actually do care about science and measure their speakers etc.
But even in the 5k-20k/speaker there are plenty of companies who are not shall we say value for money as far as sound quality goes. One name that comes to mind is B&W. They measure poorly yet are extremely popular and have a very recognizable look.
If someone was selling a 15-18" sonotube sub or even a DIY kit, I'd buy it. You can easily place them in corners, thats where I have my SVS cylinder right now.