If you go only one day by car, a tight budget would be around $1,800 MXN ($90). This should cover transport, tolls, as well as your tickets for the day trip. By bus, a single day could be enough for $1,000 MXN ($50) or less, but the hassle increases considerably. A group tour could cost between $2,300 and $3,000 MXN ($100-150)but would make the trip easier and hassle free. I recommend budgeting around $100-150 per person for a trip to Las Grutas de Tolantongo.