There are three international shipping services I use from the US Postal Service (USPS): First Class International (least expensive), Priority Mail International, and Express Mail International (most expensive). I used to allow any service for any order, which is why you were able to use First Class last time and get the lowest rate.

In recent months, I had a few packages not reach their destinations. This happens from time to time, and I always ship a replacement to sure the order is filled. The difference most recently was higher shipping volumes, and that the missing packages were very expensive (mostly during the last round of Buffalo orders). This ended up costing quite a bit to cover on my end, not to mention the hassle for a few customers (for whose patience I am always in debt).

Along with the low cost, there is a key difference between First Class and the other services. If a package is undeliverable, either because customs has been holding it too long, or some other reason, the package is discarded. With Priority and Express, not only to I get progress and delivery attempt updates, but the package will be returned to me if undeliverable.

So, these are the rules I set in place: Any order under $100 can use any service. Orders over $100 must use Priority or Express (basic tracking, insurance, and return delivery). Orders over $500 must use Express Mail.

Having said all this, there are instances when I can ship a package, say a MUX Module (5oz) via Priority or Express Mail for less than the cost listed on the shipping page. This is because USPS offers Flat Rate packaging, where, if I can fit the order into one of their Flat Rate Envelopes, I get a much better rate. When I can do this, I refund any extra shipping charges with a PayPal Refund. Since it's fairly difficult to have the web site determine what type of package an order will fit in, I can't (at the moment anyway) do this automatically. I do have some ideas on how to do it though. Until then, it's manual refunds at shipping time. This is the same process I use when combining orders: fit everything into the cheapest possible shipping option and refund the difference.

I hope this makes sense.