1. You will commit, but financial circumstances will mean you won't take advantage of the vacations (airfare, meals, etc. will be out of reach due to unforeseen circumstances).
2. A Major Life Event with Financial Consequences will strike shortly after buying (Divorce, illness, job loss) and you will be selling - probably at a loss - particularly after you figure comissions.
3. Saving money by spending less of it is not the same as saving it in a savings account or 401k. That $10,000 could be worth a quarter million when in 40 years. Would you rather have those vacations, or a quarter million dollars 40 years from now.
4. You will become addicted and a "starter" 150 points will become 800 points, with the 800 point burden of fees. Your kids will wonder what you spent their inheretance on.