After Harrison Audio LLC received my 2 slaves and master Nubus cards they repaired the 2 slaves and posted them back via FEDEX priority with a suggestion to insure them for a replacement value of $10,000. This figure they state on the invoice as replacement value – not to be confused with actual value which is subject to a customs charge.
I received an email from FEDEX to say that the package was being held by UK customs who require £1700 + vat duty. They based this on the stated replacement value on the invoice.

Here is the important bit – DO NOT SEND THESE ITEMS OVER WITH A FRIEND TO SAVE MONEY!! You need to show a record of sending the item out of the UK otherwise they think you could be importing them and you will have to pay this huge fee. Keep a record of the postage trail. Video the items not working if you can, post on youtube to share the link to prove this is genuine.
After finding all the proof (luckily) I argued that they should only charge a % for the value of the service not the replacement value. I was ready to put up a fight when my original package suddenly appeared stating ‘Customs cleared.’ There was no charge. You can imagine my relief..Hope this helps someone.