$1 today is only worth $2 tomorrow (we are talking about forgoing a 50% hit here) IF you have some way to earn 100% on that dollar - in "one" day.
Gold is useful early on but since there is no upkeep it is not something that you necessarily need right away. The main benefit would be to purchase more colonists early on to get your trade in gear. If you are just going to spend it on a Galleon you'd probably be better off waiting to purchase one with other income or building one yourself.
Open in Notepad the "GlobalDefines.xml" file and find the lines:
<Define>
<DefineName>KING_TRANSPORT_TREASURE_COMISSION</DefineName>
<iDefineIntVal>50</iDefineIntVal>
</Define>
Here 50 is 50% commission that the king takes for your treasure transportation.
There are two ways.
1. You can change "50" on "0" and your treasures will be tranported on the king galleons free of payment. I guess, it's quite far from reality. But you can do it.
2. However, there is a second and much more close to the reality way.
Please, follow the section [MODCOMP] "1 treasure per Galleon" general fix:
http://forums.civfanatics.com/showthread.php?t=294514
When you apply such changes, you could transport your treasures on your caravels, merchantmans, privateers and galleons. Of course, free of payment. Moreover, exactly in the beginning of the game where "gold is useful".
AI also prefers to transport their treasures on AI transport ships. Your privateer could easily intercept such ships and this is an additional way to earn fast money in the beginning of the game.