If he can get a UK company to ship over to America for $100 which is about £50 I think its a bargain But to be honest I don't think any UK company will post to the US.
try putting in the weight & dimensions of the full package + box etc to the USA let me know what you get
Had you thought about stripping them down to send them ET (I'm sure Sprog would do this)You could then fit them in a 1mtr x 300mm x 300mm box and that would go for just over £100 but take 28 days Having said that you could probable sell them take the cash add the £100 postage and buy a new set
I only asked DK again as I was getting over £100 too They would charge more than £5-70 within the UK let alone the USA