TL;DR:

• Alcohol $7.8b
• All illicits: $1.8b
• Meth: $0.365b

I wanted a figure for cannabis and found this from 2020:

PDF https://www.health.govt.nz/system/files/documents/publications/the-nz-illicit-drug-harm-index-2020-10-feb.pdf

• All illicits: $1.9b
• Meth: $0.824b
• Cannabis: $0.911

I notice that the per kilograms measure for harm is also useful to account for volume of usage, but think that per ‘dose’ would be better.

• Meth: $1.1m per kg with 743kg consumption
• Cannabis: $0.35m per kg with 58000kg consumption

These figures include ‘associative crime’ as harm. So it apparent counts the cost of buying it as harm, it also counts the tax loss of that expenditure, so IMHO it skews unfavourabley to higher expenditure. But put that aside.

These figures show that all illicit drugs combined are less harmful to society than alcohol, and tautologically the harm is inflated by illegality.