Valparaiso Metro (Merval) is a good way to go to Valparaiso downtown or move around Greater Valparaiso. Fares are comparable to buses. It's a great transportation method for tourists as it's clean, fast and safe. Adult fares range from CLP$204 and CLP$1080 (0.3 Euro to 1.2 Euro) depending on the time of day and the distance travelled. Please keep in mind that there is only one metro line, and it doesn't serve coastal sectors north Recreo. You'll need an RFID card to use metro, which can be recharged at each station as many times as needed.
There are also shared taxi cabs called Colectivos, that run routes throughout the city charge around CLP$500 (around 0.5 Euro) for a ride. They are quicker and more comfortable than bus.
Regular Taxicabs are more expensive but are useful if you are in a hurry. Keep in mind that taxis in Viña have one of the most expensive fees in the country, as it's a tourist destination. Also some drivers are know for trying to cheat foreigners not using or displaying taximeters, or even multiplying it's value by 10. This doesn't mean all drivers are dishonest, as most of them are helpful and friendly with tourists. Just be advised. You can also get around Valparaiso y Vina del Mar by Taxi. Uber is available in Valparaiso y Vina del Mar and and it is cheaper than regular taxis.
Colloqualy called Micro, it's the most popular public transportation method in the city. Buses vary their fare from CLP$450 to CLP$550 (0.5 Euro to 0.7 Euro) depending on the distance. Fares are published in the front window of the bus, and display Plan (Local) and Cerro fees. Plan is the way locals refer to the flat areas of the city, essentially the downtown area. The Regional Public Transport guide for Viña del Mar is published here. It is recomended you carry cash to pay the exact amount of the fare as bus drivers are known for not giving change back, unless you insist.
Further details on public transport in Vina del Mar and Valparaiso available here: https://moovitapp.com/index/en/public_transit-Valparaiso_y_Vina_del_Mar-3121
