There are three types of Taxis: Airport Taxis, Hotel Taxis and Regular Taxis (Taxi Comum). The cheapest of these are the Taxi Comum.
All taxis operate on a meter and rarely do deals off-meter. Usually it is not worth negotiating an off-meter price. Taxis here are generally good and usually will not try to exploit tourists.
The disadvantage is that in my several years here I have only come across a handful that could manage any English. Therefore, it is essential to have the details of your destination clearly written.
If they realise you are a tourist, they may well try and offer you trips to Olinda, Porto de Galinhas or other “destinations.” Organised tours with English speaking guides are a better option.