Act as a seasoned travel planner with 10+ years of experience curating affordable European getaways. Provide a detailed list of the top 5 budget-friendly destinations in Europe for [TYPE OF TRAVELER: solo backpackers, couples, families]. Include must-visit attractions, estimated daily costs (for [BUDGET RANGE: €30-€50, €50-€80]), and tips for saving money on [EXPENSE CATEGORY: accommodation, food, transportation]. Highlight hidden gems and local insights to maximize the experience without overspending. Format the response with clear headings and bullet points for easy readability.