What’s the biggest mismatch you’ve seen, heard, or done?

It happens. Whether from ignorance, expediency, transition, or plans interrupted isn’t important. Power, class, gain, size, impedance, cost, and so many other ways an audio system’s parts can differ from expectations. For years I had a CD player that cost more than my speakers and receiver combined because my intended upgrade path was put on extended pause. Right now I can’t decide on a preamp so I’m using one that cost only 1/10 of what my amp did. I see pictures of enormous speakers shoehorned into the corners of tiny rooms or someone using a flea watt amp on a power hungry speaker. I’m sure someone has used a cable that cost more than the components it connected. I’ve read about numerous impedance or gain matching issues. The objective is to entertain and educate rather than just mock (that’s going to happen a little no matter what, but try to be nice). So what’s your story?