A lot of the things that are so easy as modern conveniences were possible given enough labor to attend to them. That much gold would pay a large army, let alone a small one, to cater to your every need.
Great food? Maybe. But it has to be local, lest it spoil.
A castle? Maybe, but it would probably be cold and drafty.
Other than that you couldn't pay me $400 billion to live in the 14th century.
I'd rather have 400 million in 2012.