It is all about variable capacity. Max capacity for signed int type is 2147483647 and it's exactly what you have when gold limit (214748g 36s 47b). The author tells that you have to buy 250 gold bars with the script but you dont need to. I have found the "gold value" and it is not 250 but 189. When you use the script with 189 value you can buy much more gold bars.
Look at these numbers:
1: 114 748
2: 14 748
3: -85 251
4: -185 251
5: 144 245
it means: when you buy only 1 gold bar (1x 100000G) and you are at the maximum gold limit, you will have only 114 748g,
same when you buy 2 gold bars, you will have only 14 748g,
but when you try to buy 3 gold bars... you cant because the value is < 0
now when you try to buy 189 gold bars:
189: 212 604
it will cost you only ~2 000g
The same is with emblems but there the "gold value" is not 189. It is 131.
Sorry for my bad english, but I think you get it.