The prices of fishing stools vary widely on the market. The cheapest models start at 34 euros and go up to 272 euros.
What you have to bear in mind, however, is that with the cheap models you usually only get the basic equipment. With the more expensive models, you usually get very good padding with an adjustable reclining angle with an adjustment wheel.
Almost every fishing chair has an adjustment wheel, which is used to set your backrest correctly. However, the cheaper models usually do not have this function.