I think the difference between number 5 and number 6 is avoiding meaningless indulgences, versus not being afraid to spend money on concrete items. The booze/cigarette/ice cream is gone once you consume it, and its effects are basically over. The big-ticket item, however, might get used again and again and again. Really, the two pieces of advice are for different personality types. I am definitely the type who will not buy something even if I can afford it, simply because I am a miser. Number 5 does not apply, because I basically don't treat myself to anything, ever,
but number 6 definitely does.