"...yet he/she can accurately tell there's 235 cooked lizards in his/her backpack and 12814 gold pieces in his/her pocket."
Really? Just because there's a number in the game doesn't mean the pc knows it themselves. I mean, I doubt the pc knows that they are 'level x with y experience'.
ADOM isn't supposed to be perfectly realistic.
I'm not downvoting, btw, I just think this would be a lot of work for not much return (how many <6 le pcs are there?)
EDIT: if you really wanted to do this, just show rounded numbers, i.e. 10,000+ vs 12,000+ vs 12,230+ vs 12,235 gp depending on whether pc learning was > certain threshold values.
I think that works better than ranges of numbers (10,000 to 20,000 gold or whatever), which sounds like what you were suggesting.