I've got this soft spot in my heart for digikey, they've always shipped so quickly and called on the smallest issue and offered to help. When ever they call I always do that "why is someone from Minnesota calling me?" It's interesting how some vendors can build trust easily.
But $5 doesn't feel bad for shipping to get good parts quickly from a company I trust. But your point is taken. Sucks to put a $0.30 temp sesnor and pay $5 to ship it. =)