賃 has the 慣用音 reading ちん, as in 家賃{やちん}.
I understand that a lot of 慣用音 readings arise from interpreting the phonetic wrongly (for example 消耗{しょうこう} vs 消耗{しょうもう}), but in this case how did 賃 receive the reading ちん?
I'm having trouble seeing how it could be connected to ちん, when the 呉音 and 漢音 are にん and じん respectively.