To be honest when I saw they announced 5 additional ships and that people with beta access will get free access to one of them I kind of assumed the other 4 would cost real money - I don't know if there has been official clarification but my guess is once the 25 pledged ships are in game (and that may take some time as we have what 13 at the moment?) then pretty shortly after you will see five rather nice ships in the shop and instead of paying £10 for a chrome viper paint job perhaps access to each ship will cost say £5 or £15 for access to them all (though perhaps you then still have to buy them with in game credits as well and the access is what is charged to stop accusations of pay to win)