Free: Contests & Raffles.
I have this onehttps://www.rei.com/product/850195/cocoon-sleeping-bag-hood-pillowlove it, and it fits in the hood of your sleeping bag really well to not slide around.packs up real small too.
I just use the stuff sack from my sleeping bag and fill it with clothes until it lofts up just right.
I've used a sea to summit pillow for a few seasons now and have grown to love it. Price was steep at something like $45. But I personally get great neck support and a good night sleep from it. Packs up crazy small. Smaller than a fist. Check one out at REI before you buy.https://www.rei.com/product/866771/sea-to-summit-aeros-pillow-premium