A good lowball figure estimate your daily commute cost if driving would be to use the government reimbursement rate. It tends to be lower than what it actually costs, but it is a figure that can be referenced. Don’t ask me what it is now, because it changes all the time
'Wildly more expensive': Workers with in-office jobs spend about $31/day that they wouldn't working from home — here's what employers need to do ( finance.yahoo.com )