How rare is a 23 silver with only 6 digits? Looking to buy this in a package deal with a black eagle and a peace dollar.
Basically 1 in 100. The large-size notes didn't use leading zeroes in the serial numbers; the first serial of the block was just Z1B, and then it counted up from there. As with modern notes, 00572854 isn't really a low serial number, so it doesn't really add any value. If you can find a low serial with only two or three digits, there's significant added value there.
Like the note, however as stated here time after time condition is King, by just looking at the note your value would be very low.