Maestro Media[]
There are a lot of The Binding of Isaac merchandise, but the most popular is from the Maestro Media store. The store includes plushies, figures, and a Binding of Isaac card game. Maestro Media isn't just a Binding of Isaac store, it also has Hello Kitty, Sally Face, and many other things.
Youtooz[]
There was a collaboration with The Binding of Isaac, and Youtooz. Youtooz is a figures company, which do collaborations with other companies, or people. The two figures were Isaac, and ???.
These are a limited run, so they could be out.
https://youtooz.com/products/isaac
G Fuel[]
Another collaboration with The Binding of Isaac is G Fuel. G Fuel is an Energy formula, which you put a spoon full into water. The first flavor is "Isaac's Tears", which is flavored "White Grape Pineapple 😭", and the second flavor is "Brimstone", which is flavored "Cran-Raspberry".
These are a limited run, so they could be out.