We did livorno to Pisa at Easter, six of us cost about 36 euro return as follows:
1 euro each from cruise ship to centre of Livorno
1 euro each way bus from Livorno to the station, 3 euro return to pisa.
Bus from the crusie ship drps us of in the centre by an information kiosk. There is an archway leading past some shops, through there and cross the square. Take a number 1 bus to the station.
Train to Pisa took 15 minutes.
We walked from the station to the tourist office and picked up a free map. Then walked to the tower and back through the old part of town to the station.
Had a great day and as you can see, very cheap!