I guess I view the whole thing differently than most people.
I would rather enjoy life all year long, then go without only to live it up for one week.
Like others, I work really hard for my money, so in general, I don't like to throw it away. i'm a value based spender. If I can't see "value" in something, I won't waste my money on it. totally, subjective I know.
I have been known to take a massage on a cruise ship; generally on the first day, to increase my state of relaxation for the cruise. I see value in that. But, I will take the most basic of massages, and not splurge double for some shi-shi massage, just because I'm on holidays. A tip .... if you go to the "spa talks" that you will see advertised in the daily planners .... you will often have access to coupons or specials to save money on spa services. Drop by the spa the first day to see what sail-away specials they have .... and then go to the spa talks. They sometimes have auctions where you can bid on spa services.
For us, we spend very little on a cruise; other than gambling. We enjoy playing blackjack, and for us its like buying entertainment. We don't run up big bar bills, and we don't use the speciality restaurants. I'd sooner "waste" $100 at the tables than spend $100 in a specialty restaurant.
to each his own.