Paris has an extensive and efficient public transportation system, including the metro, buses, and trains. Consider purchasing a multi-day pass to save money on transportation costs. Taxis are readily available but can be expensive. It's also worth exploring the city on foot or by bike, especially in areas like Montmartre.
Estimated travel time and costs:
If you have more time, consider taking a day trip to the Palace of Fontainebleau or the Champagne region. Alternatively, if you have less time, skip the Château de Versailles or the Musée d'Orsay and focus on exploring the neighborhoods of Le Marais or the Latin Quarter.