Yes, that is a problem with buying feeders. Some of them are quite expensive.
You can make a simple one from a 1-gallon milk jug.
Here's an older thread with a photo of one person's version:
https://www.backyardchickens.com/threads/milk-jug-feeders.448945/
When I do it, I usually end up with the hole higher than the one in the photo (depending on the size of the chickens), and I only put feed halfway up to the hole. That way when they toss the feed around with their beaks, a lot of it stays inside anyway. And I definitely attach the milk jug to the pen, so they cannot knock it over (it's easy to tie a string through the handle of the milk jug and around some part of the chicken pen.)
If you have already have a pair of scissors and a gallon milk jug, or something similar, you can test it without having to spend any money on it.