There isn't any commission on delist. Commission on trades is 1% or 0.02 a share whichever is greater.
Is the extra commission you are think on something you shorted?
If you shorted 100000 at 100 and the price dropped to 80 then the value would show as 12,000,000, but if it actually delilsted at 90 then you would only get back 11,000,000, but that's not commission, just the difference between the price before delist and the delist price.