How are you rep 1000?

Yeah actually it's not. Possibly a slight disadvantage because it doesn't always round up based on my very limited testing, but mostly negligible. Seems that in this case with multiples of 16, it rounds down for the first 8 values in the range and up in the last 8. So really not worth the effort of doing anything about this.

And how is that an advantage? I'm not sure if it results in higher or lower amount of money obtained in general.

It's nearest multiple of 16 for my amount of money (>135000000). For less values it gives nearest multiple of 8,4,2

Ah that's how it works. Never bothered to look into the differences in numbers, but that suggests it rounds to the nearest multiple of 16 for large numbers. I could fix it by making some big number type on top of strings, but I don't really see the point. The rounding appears to be in your advantage anyway.