The rich know anger helps the cost of living:
Hating’s more economical than giving.

[Genus, Aucte, lucri divites habent iram:
Odisse, quam donare, vilius constat.]

Martial (AD c.39-c.103) Spanish Roman poet, satirist, epigrammatist [Marcus Valerius Martialis]

Epigrams [Epigrammata], Book 12, epigram 13 (12.13) (AD 101) [tr. Michie (1972)]
    (Source)

"To Auctus." Closely parallel to 3.37, to the point where some translations are cross-applied in error. The general interpretation, from Ker, is that "picking quarrels with clients saves you giving them presents."

(Source (Latin)). Alternate translations:

Anger's a kind of gain that rich men know:
It costs them less to hate than to bestow.
[tr. Fletcher (1656)]

Rich men, my friend, by anger know to thrive.
'Tis cheaper much to quarrel, than to give.
[tr. Hay (1755)]

From ire can gainmongers elicit ore.
Fell hate is frugal: love might lavish more.
[tr. Elphinston (1782), 12.68]

Ask you, last night, why Gripus ill behaved?
A well-timed quarrel is a dinner saved.
[tr. Halhead (1793)]

The rich, Auctus, make a species of gain out of anger.
It is cheaper to get into a passion than to give.
[tr. Bohn's Classical (1859)]

Rich men, Auctus, regard anger as a kind of profit;
to hate is cheaper than to give!
[tr. Ker (1919)]

The rich feign wrath -- a profitable plan;
'Tis cheaper far to hate than help a man.
[tr. Pott & Wright (1921)]

Rich men, Auctus, think of anger as a sort of moneymaking:
hating comes cheaper than giving.
[tr. Shackleton Bailey (1993)]

The rich pick fights and cause unpleasance:
Hate is cheaper than giving presents.
[tr. Ericsson (1995)]

The rich believe it pays to get irate --
to give is costlier, Auctus, than to hate.
[tr. McLean (2014)]