The value of money is interesting, I think it weighs up against the things you own versus the experiences you have.

Like my friends got their car on credit, their phone on credit, and they pay a bit every month toward it. I bought both mine outright, by saving, and waiting. My old phone and car still worked so I waited to get news one right? They work. I don't need new ones.

Then when I have an extra $100 to go out for dinner and paintball, my friends can't come, because that extra $100 goes on car and phone payment.

So yeah, the value of $100 is different because like you say, it's groceries for a week, or a night out at a restaurant, but how you use your money is also a factor in how much you value it.

I know $100 gets deducted from my pay check for my student loan. But that $100 means far less to me than if I have to pay it in cash from my wallet.