So now I am wondering whether I should indulge in NAS. Problem is that there isn't a standard charge for international shipping it is calculated on weight etc, plus there may be unknown taxes and duties...

Also - reading the returns section I am not 100% clear on whether I can return items to a store. I will be in Seattle and San Francisco in late September / early October so I would do any returns then.

Here is what the website says:

"Returns & Exchanges
We cannot offer merchandise exchanges on orders shipped internationally.

International orders must be returned via FiftyOne and must include a Return Merchandise Authorization form. Please contact Customer Service to receive this form. Refunds on international orders include duties, taxes and tariffs when sent with this form to FiftyOne. FiftyOne will credit your account upon receipt of the merchandise at the international hub.

Returns sent without the Return Merchandise Authorization form may not be refunded the full amount. Unfortunately, we cannot refund your original domestic and international shipping charges. We cannot refund duties, taxes and tariffs if an item is returned directly to a Nordstrom store. We cannot offer free returns on international orders."