Ford Focus engine oil leak

Depends where leak is i.e top of engine or lower .If lower might be the common fault of sump rusting . If top , could be cam box gasket .

if its the lower part of engine oil leak whish is slum how much to repair it,for focus 1999model lx manual 5 doors

if its the lower part of the engine which is the slum part how much will it cost me,ford focus 1999 model lx manual 5 doors