You really need to split "gold ones "up.

 There are in band releases. Then there are extras.

 So the mintage of loaded 1000 bitcoin bars is extremely low. Less than 10.

 These coins being made available, we're not known to have existed until Charlie lee announced it. Mintage is not known, but they are a separate collectible.

 There are direct parallels with the unfunded casascius bars.
 These are both different from an in band release which has been redeemed but still has its collectible unique first bit hologram.

 We can look at how much low mintage items have sold for in the past.

There was a first day coin - 1 btc -  which sold for 50 bit coin.
 There is a series to stick a coin with a mintage of only 45. Those have sold for, I forget now, let's say 20 bit coin for a one bit coin coin.

 When you get to mintages lower than that the sample size is smaller.

 The 100 bit coin bars now have a mintage of about 16 left. I have sold those for premiums of...more than 50 bit coin.
  The 1000 bit coin coin's have a vintage of five or six. I believe Goat set the record , when he sold a 1000 bit coin coin for $1,250,000 or 1250 bit coin.
 Rarest is the 500 bitcoin bar, of which only one exists for each version.