I did see a TV ad yesterday that Southwest is having a "sale" with some one-way flights for $69 in August/September (?). Since their flights are only listed on their own web site, you have to check around.

It used to be that there were often charters from reasonably-sized cities to Vegas/Atlantic City for gamblers. Dunno if that's still a thing now. A human travel agent should know.

Good luck!

Cheers,
Scott.