The currency in Portugal is the Euro, and typically goods and services in the country are cheaper than in neighbouring Spain.
Tipping is not compulsory in Portugal, although generally 5-10% of the price of the meal is left in restaurants - unless service is specifically included in the bill.
Taxi drivers usually expect to keep the change, so its not a good idea to give them a high value note to pay for a cheap journey.
In larger shops, bargaining is not welcomed, however in markets you may well be able to get a discount - provided that yoru Portuguese is reasonably good.
