Trader sells costumes for free.
You can use old save files but companions and unique characters have default customization settings.
If you updated this patch form old version, you should load old save game file and press export landscape button. or you will see ' critical bug : landscape not found' message box when start new game.
Player have to adjust height manuelly. I will add auto adjust button soon.
https://youtu.be/qq2wY8P7UTA