Can someone advise me what bus to get to Esposende from Porto. Would it be expensive to get a Taxi??
It's 52km/32miles from Esposende to Porto so yes a taxi would be very expensive.
The Rede Expressos network has a couple of journeys to Esposende from Porto, cost €7,70
details at www.rede-expressos.pt
the AV MInho bus company also runs from Porto however most buses start at Povoa de Varzim, to where you can take the Porto metro red line from the city.
You can also take the Metro to Povoa de Varzim and from there a bus to Esposende.
Check also this site with other buses companies:
Renting a car is also a good option.