acoustic foam

I'm trying to do some sound treatment in the room I'm using for my home studio on little to no budget. I was given a piece of this acoustic foam from a friend that had some left over. It's 2.7 metres by about 1 metre.

I recently replaced the acoustic treatment with some new acoustic tiles in my home soundroom.
These are strategically placed such as first points of reflection, etc also four centred on the main oposing wall followed by a line either side along the centre at evenly spaced intervals, also some corner bass traps.

Dear Forum, I have a home studio that I use for doing sound design for theatre, mixing acoustic theatre (theatrical installations and radio drama) and composing electro-acoustic music. I'm gradually diminishing the reverb in the room and I'd like some advice please on further steps I can take on a low budget (we renovated this house recently so I'm doing things slowly!).

Guy in area is selling his "high grade, high density professional acoustic foam"
He's selling the 2 in. thick 2 ft x 4 ft panels for $12 each.
And the 3 in. thick 2 ft x 4 ft panels for $17 each.
Here's the manufactures site of the product.

Kurt,

If you want to compare foam to my products, at least do it fairly. That is, show the relevant frequency ranges. Since you are either unwilling or incapable of providing a fair and unbiased comparison, I request that you edit your post to remove all references to my company's products.

Thanks.

--Ethan