Players spent a lot of gold to roll the extra yellow dice to increase the odds of getting reasonable camel numbers, but this was only of limited effectiveness.
That seems like a tough way to go. With 3 gold dice, you're only adding an average of 1/2 camel. 3 coins for a half camel is a bad deal. In fact, you can even hurt your camel count. Suppose you'd normally roll no 1's and two 2's. Your gold dice are 2-2-1. On the surface you'd expect to increase your camels by 2 because you now have four 2's, but of course now the 1's take precedence and so you've only got one 1 - and one camel to take.
It seems to me to be better to just roll and if you don't like the results to take a card. There are some cards that award you 3 camels and some that let you trade gold for camels. Like that 3 gold you'd otherwise have wasted.