I recently made a few purchases from lendmeurears.com (great seller, definitely recommend them!)
I am a little ashamed to admit this, but I just figured this out.
They offer prices in USD as well as their native currency, Singapore Dollars.
In my haste, I always checked out in Singapore Dollars, figuring it would all work out in the conversion.
However, Paypal charges 2.5% over the exchange rate to process international orders.
So, if you are given the option of making the purchase in USD instead of the foreign currency, do it!
They should get the same amount, and you save the 2.5% on conversion.
Luckily for me, this amounted to just a few dollars on my orders, but for those making big purchases, this could add up.
Anyway, sorry for a thread about something so obvious, but hey, it's worth it if it saves someone some money!