Rattitz Saga: Piccolo was around 456.
Saiyans Saga: He was in between 1100 and 3000. At the beginning he was 1100 but when he got really angry he got up to about 3500.He died in this saga.
Frieza Saga: Before the fusion with Nail he was about 45,000.After the fusion with Nail he was around 150,000.He was brought back to life by Dragonballs.
Cell Saga:After the trip to the Hyperbolic Time Chamber and the fusion with Kame he was at 15,000,000.