IRS already has a calculator for this very thing it’s about $.75/mile in reimbursement. If the round trip is about 240 mile one way the. A round trip puts the reimbursable cost at $360. Add in hourly wage let’s say $15/hr let’s say it’s a 7hr round trip that’s $107. That’s roughly $467. Now add the cost of the toy. Puts it around $500 for that $30 plushy in time for her son’s birthday. So your $540 is very reasonable.