Infinitely cheap. But the value is in the information not the letter itself.

Money is information not the physical, note/coin itself. The only reason 1/10th oz of gold is worth less than 1 oz is because we have the information that one weighs more than the other. The only reason 1$ bill is worth less than 100$ bill is because of the information printed in it.

Money is energy density, bitcoin is by far the most dense. Money is representation of calories and watts. Bitcoin is a direct measure of calories and watts. Gold is an indirect measure of calories and watts. Fiat is an obfuscation of calories and warts.