Ouch. that feels unfair as you dont control the value the seller declares.
Also, it's customary business practice to declare low values on packages, i think it's intrinsically why prepaid shipping exists: if that includes VAT, it implies a low value inside the box.
Also, the 80 is probably the real cost, w/o shipping. did you make that argument? a large portion of prices on AliX are shipping costs, so if you paid 200, 120 shipping, 80 product, it actually feels legit. you can go on alibaba and screenshot the same stuff, you'll probably see prices in this neighborhood.
The fine is unfair as it's just punitive.
Are you sure you can't reject the parcel?
did you contact Aliexpress? it must be the sort of thing they hear about very regularly.
I guess you shouldnt have sent them proof that there was a discrepancy between the 80 & 202? Maybe pretending it was a gift, or that you won the item, or that it was warranty replacement? Because you kind of gave them a smoking gun.
But even then, the fine is just unreasonable. it's not like you're a business defrauding the state, you bought cheap stuff that was declared as even cheaper.