The value of gold is not a constant, it depends on the availability. So a plausible explanation to abundance of gold in your generic fantasy world would be that in this said world, gold veins are more accessible and/or much more common.
However, I would also like there to be denominations, as it adds to my perception of in-game world being more similar to real world and therefore more realistic
Yeah, that was just shortcut for my point. About your example: in world, where gold is that cheap, we would pay about 10-100k for really expensive items;
"Sure, I have 45 371 coins in my pocket"
And this is really not real world alike
(Yes, sure, here came never-ending discussion about having whole armory, small farm and one troll body in your backpack. But this thread is just about currency.)