Price it right and it will generally go, assuming its actually stuff that people want. If you watch, you can see what similar items are selling for, and as a hint, it its sitting out there for weeks, its priced too high - and that's why it sits.
I've sold cars, car accessories and parts, bikes, car stereos, etc... Bought similar things. Never an issue.
Also had decent luck with Facebook Marketplaces. Letgo, not so much.