Studio foam looks worlds better, so if it's for clients, then I'd go with the foam.
If it's just for you and cosmetics are not a concern, then I'd go with a big heap of moving blankets. I just got 10 of them (about 6 feet by 4 each -- and real thick and heavy) for $12 / piece. I love 'em. So portable, so versatile . . . so . . . heavy. I'm ordering 10 more next week.
Drape one over a couple of mic stands for a makeshift gobo. Hang a few more on the wall. Stack a pile of them in the corner for a bass trap. Scatter a few around the guitar amp. Take another with you to the park on your next picnic.
Lots of sound can hit them on one side, but not much comes out the other. Such a grand concept. What an invention.