In my opinion, it is wrong to pose the question: what will be more expensive, gold or bitcoin? What will we compare with - an ounce of gold with Satoshi or Bitcoin? We can only note the rise or fall of the price of gold or bitcoin for a certain period. Although I believe that these two financial assets are practically opposite in their functional capabilities and most likely, they can be considered as complementing each other, and not competing with each other.
I tend to agree, although I think Bitcoin is a better investment for several reasons:
Gold Advantages:
- Can't lose your private keys
- No learning curve, it just sits there
- Looks nice and feels good to the touch

Bitcoin Advantages:
- Shipping/transport cost is much lower than gold
- Much easier to buy/sell anytime and anywhere
- Much easier to make sure it is not counterfeit