You are confusing the charge with the penalty mate. You only have to pay the penalty if you don’t pay the charge. Charge is £200 :-
LEZ daily charges
We would prefer that your vehicle meets LEZ standards. However, if you’re not able to take the measures needed, then you can drive within the zone by paying a daily charge.
Vehicle Weight Daily charge
Lorries - Goods vehicles More than 3.5 tonnes gross vehicle weight £200
Motor caravans
Motorised horseboxes
Breakdown and recovery vehicles
Snow ploughs
Gritters
Refuse collection vehicles
Road sweepers
Concrete mixers
Tippers
Fire engines
Removals lorries
Other specialist vehicles
From here :-
tfl.gov.uk/modes/driving/low-em … -a-payment