Yes, we agree with multapaakku! 🙂 I just want to add one more point. Who made the brush also makes the brush special. Sometimes, you might feel all the brushes look alike. However, they are not at all. More experienced brush craftsman knows way much better about what type of hair should be used for which type of brush, how the hair should be processed, etc. All these are crucial elements for a good brush.
And, we do not think these brushes in the photo are for collection purpose. However, if the brush is more for practical use, this also means each brush has its own lifespan. You will need to try them and feel how well they can still serve for your painting purposes.
We do have some tips to help decide the value of brush. You can refer to,
The value of the brushes also depend on what is the appraisal they have been given and by whom, how old they are, how rare and what is the type of hair used to make them and most importantly what value they hold in the eyes of the buyer. in my opinion the 4 treasures of the study are not something that can be limited by monetary value.