In yoga, there are eight areas of practice, two of which are Yamas (moral restraints and disciplines) and Niyamas (self-restraints and observances). There is a good explanation of the yamas and niyamas here. One niyama is Santosa, which translates as modesty, non-greed, contentment with what we have.

From that link:
is having a sense of modesty and the feeling of being content with what we have. To be at peace within comes from fostering contentment with one’s life, even while experiencing its challenges.  When we accept that life is a process for growth all of the circumstances and experiences we create for ourselves become valid teachers and vehicles for expressing our highest nature. Accepting that there is a purpose for everything – yoga calls it karma – we can cultivate contentment and compassion, for ourselves and for others.  Santosa means being happy with what we have rather than being unhappy about what we don’t have.

The easiest translation of this I’ve ever seen is, “Want what you have. Don’t want what you don’t have.” When I’m feeling the constraints of my budget (or lack of one), this is something I say to myself often. It’s akin to walking through Target (where I can spend $100 in 15 minutes) and repetitively saying to myself, “Buy what I need, not what I want.”

Santosa is a good topic to meditate on. When meditating on santosa, we’re thinking about wanting what we already have, and being grateful for it and satisfied with it. And we’re thinking about not wanting what we don’t have, not craving or desiring. The craving, desiring, and clinging to what we already have is what causes so much stress and suffering.