User blog comment:B214/Volume 17 spoilers./@comment-117.193.172.96-20140220062652/@comment-24468758-20140220080016

Issei is the reason they could come up with oppai dragon and because of this they were able to attain that money. Additionally I never said anything about the finances of the Gremory clan that had a huge palace as a main residence with many other residences even long before oppai dragon started. Lord Gremory's idea of a souvenir is a very good example for their wealth.