From ὄψον cooked meat, and later, generally, provisions. At Athens especially fish. Hence ὀψώνιον is primarily provision-money, and is used of supplies for an army, see 1Co 9:7. The figure of Rom 6:13 is carried out: Sin, as a Lord to whom they tender weapons and who pays wages.
Death
“Sin pays its serfs by punishing them. Its wages is death, and the death for which its counters are available is the destruction of the weal of the soul” (Morison).
Gift (χάρισμα)
Rev., rightly, free gift (compare Rom 5:15). In sharp contrast with wages.