To explore Montenegro in one day, it's recommended to rent a car or hire a private driver to save time and make the most of your day. The cost for a rental car is around $50-$70 per day. The total transportation costs, including fuel, tolls, and parking fees, are estimated at $30-$50. However, keep in mind that the roads in Montenegro can be narrow and winding, so it's essential to drive carefully and plan your route in advance. The total travel time is approximately 6 hours, depending on the traffic and road conditions.
If you have more time, you can add other sites like the National Park Durmitor or the Ostrog Monastery to your itinerary. However, if you have less time, shorten your visit to Perast or Budva or skip the Mogren Beach stop. Remember to bring sunscreen, sunglasses, and comfortable shoes for walking.