Re: Letter from America..... No not the Proclaimers
It depends entirely how they were mailed - small packages of picks and strings are likely sent via the US Post Office, First Class Mail International. That takes generally 3 weeks. Except for shipments to Wales, I have no idea why it takes an extra week or two to get there. Maybe it's the lack of vowels. That costs around $11 US, though.
We're also shipping from the upper left corner of the US, so part of our shipping time is across our own continent.
There are cheaper bulk options, but I've never used them. I've had shipments to me (US address to US address) take more than a month using the various bulk mail rates.
We ship custom pickups, trim rings and various other hardware US Post Office Priority Mail to the UK, with delivery confirmation and that takes about 10 days, and we have to use a third party to have insurance (up until about March of this year, the USPS offered the option of insuring shipments over $100, now they don't). That's all around $45. There isn't really a tracking service - all you can know is if it is delivered or not, not where the pkg is in shipment.
Before we discovered the third party shipping insurance (a set of pickups and rings is around US$500, so we don't ship without it), we were having to use US Post Office Global Mail, and that was running about $85 and took 5 days. UPS was about $125, FedEx was about $170. Not really worth it on a $500 item.
1918 Gibson A, "Lillian";
1940s (?) Kay A style f hole - currently down for a refret and fretboard re-profile, my first attempts (with guidance) at lutherie.
1981 Washburn M7SN (2 point);
2011 Eastman 504, "Belle";
2012 Lafferty mahogany octave mandolin;
2012 Emando (Saga), "Hank"
1 husband, 2 dogs, 4 chickens.