Is Garry's Mod worth buying?

Of course! Garry's mod today is still such an amazing game, and you'll be found by how still popular the community is.

since it's open source, you can pretty much do anything you want with it so yeah, it is a great game

yea, i really enjoy the game, would recommend buying it.

yes it is. you would not regret it

It is best to wait for a sale on GMod, but the game itself is a great tool for videos and or weird antics to do on your own or with friends. Plenty of community contribution and solid multiplayer servers and game modes.