How to implement DLC with unity free?

Okay, so I know that AssetBundle is a great way to implement dlc, but since I can't afford the pro version that is $1500 which is about 10,000 SEK and that is really expensive for a software, ridiculous. Okay, so how do I implement dlc to my game? Could I simply check if a folder contains certain data such as assets and then load them as I want them to be loaded? Or what? I'm really into dlc's and I wanna make one but I don't have the money for unity pro, so is there a free way to do it?