Lost input after changing price package

Guys,
of course we would like to have our endusers to change their mind while entering their data. In other words: If they decide to upgrade themselves from a free to a paid listing that’s good.

But we’ve noticed an annoying thing: All data that an end-user entered is deleted/removed after they change their price-package. This is definitely a conversion-killer. So If you would consider to change this (cookies??)… much appreciated;-)

Thanks again. Keep up the great work!