Drink prices in Tenerife can vary widely depending on where you go, what you order, and the level of touristiness. Here’s a general breakdown to give you an idea (prices are approximate in Euros, €).
Prices drop significantly when you venture away from the main strips. Local Beer (caña): €1.20 - €2.00 Copa (small spirit with mixer): €3.00 - €4.00 Glass of Wine: €1.50 - €2.50 Coffee: €1.20 - €1.80
This is by far the cheapest option if you’re self-catering or having pre-drinks.