I didn't know this! Good to know now, though. I purchased something from there and then paid additional shipping. Will know for next time. Thanks!
Also of note - when you submit an offer, it's for the total you're willing to pay including shipping.
I learned this the hard way when I accepted an offer for an item and was paid that amount only, and then needed to pay shipping out of pocket. Not a biggie, but could be an issue if your seller doesn't know this and doesn't want to ship without an additional payment (or isn't willing to spell out terms: offer for item, plus shipping for $XX total.).