For most of history prior to the 20th century, 10kg of gold would have bought you quite a fancy house. It would be about 140,000 roman Denarii, or roughly 120x the wage of a legionary.
If you look below, the comments did the math; Same amount of gold.
The main issue is that gold isn't directly used as currency, so this post is really saying "if you bought something worth a house, it is worth a house. Isn't that weird?"
Gold used to be directly tied to our currency, but you can't just print more money when it's based off a gold standard, and the government didn't like that, so they changed the standard.