Dude, you are not being an asshole, you are completely on point. Your friends are turning into one-dimensional loser pot-heads. You should just separate from the group and meet other people.

The thing you said about how they're cheap as shit and complain about spending money on anything besides pot is very true. I have a few friends like this and shit sometimes I get like that when I'm depressed.

One way to solve it is to take them all out to a bar and get them shitfaced. Sometimes a night of drinking and doing stupid shit really brings back that excitement in life.

You're maturing a lot faster than your friends, so you should either try to get them on your level or get friends that you can chill with and have fun. But you should in no way drop to their shitty pothead stage.