Thats really cheap. I wonder if they get you with the shipping... to be honest though, they could probably just pack those things in an envelope and send them for free so it would be a major ripoff if they charged much for shipping.
Oh hot damn. That is $12 each cap so $48 for 4. Then they wanted $16 for slow shipping and $54 for fast shipping. Are you freaking kidding me? $64 for stem caps? Or $102 if you want them in 1 week instead of 2.