。
I couldn't even afford to buy a bicycle.
Literal
I [to-は] bicycle [object-を] buy leeway [like-なんか] not-existed.
なんか is a casual/colloquial focus particle — adds a slightly dismissive or emphatic 'like, anything like' to the preceding noun. Here 余裕なんか = 'anything like the leeway [to afford...],' making the statement more emphatic and complaint-flavored. Past tense なかった marks the historical state.