A heavy purse makes (for) a light heart.
Note: This seanfhocal celebrates the things that money can buy, particularly freedom from material want. Perhaps “money can’t buy happiness”, but poverty is surely no guarantee of bliss.
Note also: The Irish antonyms (opposites) for “heavy” and “light” are obviously related. The basic form is “trom” (heavy) which is converted to its opposite by prefixing “éa…” yielding “éadrom” (light). The change of the ‘t’ in “trom” to a ‘d’ in “éadrom” is just due to a normal shift in pronunciation, and does not occur in some dialects.