France can be done affordably. Paris is expensive but manageable: a budget of €80-100/day covers a hostel, baguette lunches, museum passes (the Paris Museum Pass saves significantly), and metro travel. Free sights include many churches, the Sacre-Coeur exterior, and the Palais Royal gardens.
Outside Paris, costs drop noticeably. A mid-range trip of €150-200/day in the provinces covers a comfortable hotel, sit-down meals with wine, and car rental for rural exploration. The TGV high-speed train is excellent for city-hopping.