Directly to get from Keszthely to Nice will not succeed, transplants will be required. First you need to get from Keszthely to Budapest. By train this distance can be overcome in about 3, 5 hours, it will cost about 11, 5 - 14 EUR

The bus route will be longer, but it will cost from 8, 5 EUR per person. Further on the bus it will be quite inconvenient to follow, considering the intersection of many borders, the distance and the fact that the railway carriers offer a very worthy service for the money they are making.

Further it will be most convenient to follow to Nice via Venice - the Budapest - Venice train, the ticket price is 55 EUR. From Venice to Nice there is a direct night train, the price of tickets varies from 30 EUR per seat to 170 EUR per compartment