Thank you @hivehustlers!
The big tent is 8 feet wide, 4 feet deep, and just under 7 feet high. It's quite large, and priced decently with Vivosun, under 300 dollars USD for that big tent.
The other tent I use is pretty much half the width, and also decently priced Vivosun product.
I've never used any other brands but really love this brand. They make good quality tents.

I'm not sure how much space mushrooms require, but that is super cool and also something I'm interested in cultivating in the future, but I don't feel I'm ready just yet.