The exact value of a can painting by Janicotte would actually depend on a couple different things. Some of these things would include the age and condition of the painting.
I have one, unframed, 28 x 22 cm. "Flower seller, Paris". I paid £8 for it early 2007.
Prices in art vary widely depending on of the artist, but also of numerous factors. Is the picture a real, original watercolor, or a litho, or a reprint of it? A reprint would be sold for just a few euros, a litho could fetch more, an original, unique watercolour would be more costly.While we can find the name of Janicotte on the internet, a painting by him isn't going to fetch a very high price. A couple of lithos by Janicotte (including a view of the Arc de Triomphe), in good condition, can be found on the internet at a starting price of $20, with an estimate of $100 to $200. Looking to the lithos, I would say that you could find equivalent worl for less, but art price is subjective.