I don't think this request is at all out of line. Yes, the OP did leave the items behind, items that they were responsible for. But, it isn't as if the OP is asking for the hotel to mail these out on their dime. They offered to pay for the postage, I don't see anything wrong with that. I personally LOVE Bill's suggestion of taking this issue of to the manager. It would be one thing if the pillows had already been tossed. But, as of the OP's phone conversation with a staff member, they had not been. So the quickest way to resolve this situation if you ask me would have been to take the issue up the chain. This ensures that the OP gets a final answer quickly prior to the pillows being tossed, lost etc.