Yea, some of the people who are unluckily part of my smoking circles act like this. They won't throw in, but they will feel free to invite whoever over all the time for a free smoke.

The guy above has some good advice, try talking to him. Tell him it's putting hitting your funds hard and while you don't mind smoking people up sometimes, they never throw in and you can't keep doing this.

Either he'll get it or he won't. If he doesn't, I'd try to get bud without him even knowing... I wish I could give more advice. I quite haven't figured out how to solve my own friend problems, besides just avoiding them. So good luck.