"About how much is the customs fee? TIA"
If you are in UK, about 35 Pounds each, if you're in the good ole US, $0.
I paid 216 for 9.
But there was no consistency in the charges. I received 3 invoices (as the Ants were 3x3) and each got a different amount.
It's a price based on the spot USD/GBP rate.