You could make one. There's even kits available. Making your own pedals is a rewarding side hobby to playing electric instruments.

I saw a Little Big Muff on amazon for 63 bucks.

the Behringer Super Fuzz SF300 is crazy inexpensive. You can find it online for less than $30, and it’s a lot of fun to play around with. You won’t get the same fat tones you can get from a muff, but it’s still pretty flexible.

Big muff is not a massively complicated circuit, those Aliexpress ones are fine if you just want the sound. Some of them are fairly highly regarded as is like the ones from Mooer

I think they're cheap enough to give one a go until you know more what you might want to spend more money on.