No, you can sell even bare domains on Flippa. There are also "starter sites", growing sites with 5 figures a month in revenue and pretty much everything in between.

I know you can, but it won't get you much these days.

Edit: aka if it is a good idea, it is probably better to find someone to take it over for a gentlemen's agreement of a % later than tossing it away for a few $. IMHO of course.