I would like to purchase some very nice sea salts. There are many sources available online but it is hard to tell what their quality and reputation is. What is the most comprehensive online shop for purchasing sea salt?
While their selection of salts isn't the broadest ('only' eight or nine varieties) I'm a huge, huge fan of World Spice ( http://www.worldspice.com ) here in Seattle; I've never mail-ordered from them but every time I've dropped in to pick something up the staff has been immensely helpful and knowledgeable.
MySpiceSage normally has great prices for everything, including salt. Quality has been good on everything I've ordered (thought I haven't ordered salt). They are constantly running new offers - today's you receive 8 free vanilla beans with an order - and you always get a 1oz sample of any seasoning you want with every order.
I have purchased several products from http://salttraders.com/
Their smoked salts are amazing.
If you are outside the USA email them re shipping as their web site only uses expensive couriers whereas if contacted directly they are happy to use US Mail for international shipping.