Defence lawyer Barry Roux said Pistorius was both “broke and broken” after the seven-month trial.
Pistorius was convicted of culpable homicide last month after shooting dead his girlfriend Reeva Steenkamp last year, but was cleared of murder.
Judge Thokozile Masipa is expected to deliver the sentence on Tuesday.
There is no legal limit on the length of a jail term, but the prosecution has argued for a minimum of 10 years.
Experts say the typical maximum sentence for the crime is around 15 years.
Pistorius’ defence team has argued for him to be given community service and house arrest, a suggestion the prosecution said would be “shockingly disproportionate”.
Both defence and prosecution lawyers finished presenting their final arguments before the court was adjourned.
The high-profile trial, which has captured public attention in South Africa and beyond, began in March.
Pistorius sobbed as Mr Roux said the athlete was once an “icon in the eyes of South Africans” and now could not even pay for legal expenses.
“He is not only broke but he is broken,” he said.
“He’s a first offender. What has happened to this man? He was on the rise,” Mr Roux added.