We were talking about marriage and the amount of money we can bring to the table, but why does the amount keep changing so drastically?

I have nearly 400 million won, but my girlfriend initially said she had saved about 20-30 million won.
When I told her that even if it's not as much as I have, I'd like her to have at least a certain amount,
she said it was 40 million won..
Is this even possible? Is this something that can be easily lied about? What do you all think?