The official currency in Ecuador is the U.S. Dollar
(advice: is better to change your money in your country, because the Exchange Offices here charge you a comission)
In the big cities (Quito, Guayaquil, Cuenca, Machala, Loja) Hotels, and Restaurants most of credit cards are accepted, Diners, Mastercard and Visa are the most accepted.
Tipping: always is optional, the Taxis don't expect Tips.
Most of Restaurants always charge you a 10% service fee
Food: from US$ 1.50 (one "Almuerzo" in a popular restaurant) to US$ 10.00 in a Restaurant
Room: Depending a lot of the size of city (bigger is more expensive), from US$ 5.00 or 6.00 ( in hostels and popular residences ); US$ 30.00 in a three star hotel; US$90.00 or more in a five star hotel. If you plan to stay longer, you can host in a family for $US 10.00 - 15.00.