Monday, November 10, 2008

Cost/benefit analysis

Conventional wisdom says that, to get the best value for your money, you should always buy in bulk, never buy small packages, and never never get anything out of the vending machine.

But is this always true? Can a case ever be made for buying something out of the vending machine, and moreover, is there ever a situation where it truly is the best value for your dollar?

Here’s the situation. I usually eat a carb-y snack in the afternoons, but because I’m trying to lose some weight, I don’t want to have a huge bag of pretzels or box of crackers lurking at home or in my office. So I have an optimization problem. How do I balance my desire to spend as little as possible on snack food with my desire to keep temptation at bay?

For comparison, one bag of pretzels from the vending machine costs $0.90. That’s $4.50 per week for snack food. Kind of pricy, but because of the price and the fact that I have to go all the way downstairs to get it, I only eat one a day.

A box of crackers from Trader Joe’s is about $2. It has 8 servings in it, and, in theory, should last me an entire week and has less than half the cost of a week’s worth of pretzels. Empirical evidence suggests otherwise. The last two weeks I’ve brought a box of crackers to work it’s been empty by the end of the second day. And then I bought pretzels the other three days. That adds up to $5.50. This is a bad deal for both my wallet and my waistline.

Pretzels in bulk have the same problem. It’s only about $2.50 for a large bag with about 17 servings. That’s a little more than 8 days worth of vending machine servings. Definitely a better deal, price wise, but I can guarantee you that I’d eat the whole thing in a week. So is it worth $2 for me to eat only 5 servings of pretzels per week rather than 8.5? I think so.

So using my own cost/benefit analysis, I believe that buying pretzels from the vending machine is definitely the best deal for my wallet and my waist.

Quick Diet Update- Rather than giving up pretzels and crackers and worry about what I can and can’t eat after dinner, I’ve worked out a weekday meal plan for myself. I’ll spare you the details because it’s not interesting, but I’ll be tracking compliance on my HabitCal now. And because I’m not going to track soda anymore, I’m going to start tracking No Gum. I feel like that’s a better replacement than eating after dinner, which is going to be covered under the meal plan anyway.

Recent workouts:

12mi in 1:48:28
Bikram’s yoga
Walk 2mi on treadmill
2 sets of stairs
Walk home
Upper body and core sections of DVD