I quit smoking 57 days ago. I found having a goal helps keep one motivated to not pick up the next pack of cigarettes. There's an Android app Quit Smoking that helps me keep "score" of my progress. It has a health chart with a progress meter, you can set a goal for money savings, and keep a diary within the app.

I set myself a goal of buying my two sons a 700€ game computer and I've already saved 155.55€, there's 200 more days to go. I'm pretty confident I can make it.

Good luck quitting!