Afford is a native Old English word from geforðian ('to further, accomplish'), which shifted from 'to carry forward to completion' to 'to have the means for' during the Middle English period.
To have enough money or resources to pay for something; to be able to spare or give up; to provide or supply an opportunity or facility.
From Old English geforðian ('to further, accomplish, carry out'), composed of ge- (a perfective prefix) and forðian ('to further, promote'), from forð ('forth, forward'). The original meaning was 'to accomplish' or 'to carry forward to completion'. The initial ge- was lost in Middle English, and the prefix was reinterpreted as a- (the common reduced form of various Old English and Old French prefixes). The modern financial meaning — 'to have the means for' — developed in the late Middle English period, shifting from 'what
Unlike most words starting with af- in English (affair, affect, affirm), which come from Latin ad- + something, 'afford' is a native Old English word. Its apparent Latin-style prefix is an accident of sound change — the original ge- prefix dropped away and the remaining form happened to look French.