Onward Tickets from Kraków to Nan

Do I need an onward ticket to enter Poland?

The foreigner must have the return ticket or funds to cover return travel costs to the country of origin or residence or cost of transit to a third country which grants the travel permit, in the amount which is equivalent to the cost of the ticket, on the basis of which the foreigner arrived on the territory of the Republic of Poland, which is however not lower than: