In the trading market,
even if it's the same great artist's work created around the same period, and the dimensions are similar, theoretically, the selling prices should be similar as well.
In fact, counterintuitively, there are often price differences of several million US Dollars or more between these different individual pieces.
The reasons for these fluctuations, excluding the different historical contexts of creation, the public's perception of notoriety, and variations in exhibition records.
The biggest influencing factor is the artist's state of creation.
Some paintings are poorly executed, which may be due to the artist experimenting with new techniques they're unfamiliar with, or suffering from a professional ailment like an occasional bout of wrist arthritis.
And some... they just didn't really put effort into them.
