Nissan Primastar 06' - Temperture gauge - Froggy 38

Hi All,

I'm having a problem with my van Nissan Primstar 06'. When i am driving at speeds of between 80 - 100 kph the temperture gauge shoots up to the max. The red warning light comes on, and the altenator/engine sign. Do you think this will be expensive to fix? Should i get ready for a large bill?

Regards

Froggy 38