Honestly, in hindsight, I am really bad at seeing the implications of my quality of life at the time of purchase. Part of it is due to changes in personal habits that I don't always foresee. For example, I play significantly fewer video games than when I was in college. But it's also due to my perception of what it should cost versus how much I use it. An example of that would be some of the nice clothing I own that I paid extra for. I wear it enough to justify the cost. Then there are the non-tangible things like vacations which have given me some amazing stories that I would not have imagined.<p>Though that speaks more to the concern over the quality of what I get, or whether I should own or rent something. In practice, as a young, single, physically active engineer who lives in the Bay area, (aside from clothes, food, shelter, and transportation,) I get my 80% value out of the following:<p>Running shoes, a bike, a good backpack, a gym membership, Spotify premium, a good computer or two, a good smartphone, and the more than occasional airline reservation.