http://www.growstone.com/about/products/soil-aerator-2/

Has anyone used this product in their soil mix for container plants.

I am wondering if this would be a good purchase since it is expensive.

Hi,
Are you sure that this is labeled for food crops ?
This product is made of recycled products and wastes, and the tags says it is for ornamental plants.
I wouldn't risk it on food crops, for health concerns.
To aerate a potting mix, one can use pine bark chunks. It is cheap.
Normally, standard loam is just as good for figtrees.

Lara rock is inexpensive, it has lots of holes as well, if you smooth out slightly sharp edge that not to good for roots, it is cheaper and easier to get then this new product.

Also, easier option like air pot or net pot can do the same thing, but I think that media dry out fast, and you might need to use drip irrigation system.