I'm curious how you think Trump will fund a general election bid. Is he going to do it without spending money? That might be a trick, once the media no longer cares about giving him time to trash the Republican field.
If he is to spend money as others have in the past, history would put that number at about $1 billion. Now Trump is a rich man, but he's not that rich. He doesn't have a $1 billion in cash or fluid assets, and even if he did, I doubt he would spend the majority of his wealth on a run.
So where will the money come from?
I think it would really hurt Trump to actually have to spend his money. Maybe on an 80 ft living room or a foreign trophy wife but ...
Where would Trump be without his celebrity which gained him all the free media coverage?