The people who live beneath their means tend to be careful with their money (unless they have a very large amount of it to begin with), so they are unlikely to completely ignore the cost of things like travel or education (even though some may be willing to spend a lot more on travel or education in comparison to other things that they may spend money on).
It is only the wealthiest who can afford to find it distasteful to consider the cost of something.
Many people spend freely on medical care because their medical care is mainly paid by third parties (government and/or private insurance companies). It is easy to spend someone else’s money (and spending money for medical care that is of dubious value in improving medical outcomes may be part of the reason for the rapid rise in medical care costs in the US). When people have to spend their own money, they are likely to give much more consideration of cost (e.g. the threads where people age 50-59 discuss whether a $200 shingles vaccination not covered by insurance is worth it).