Looking for reasonably priced sound diffusion.

I am looking for sound diffusion panels for placement on my ceiling. They need to be lightweight (no holes in the ceiling) effective and reasonably priced. No more then $80 panel or so for 2X2 feet. Like to actually spend less.

I have seen products by RPG - Skyline and Auralex - T-Fusers. The Skyline is to pricey. Not sure about those plastic looking T-Fusers.

I have good absorption and simply want to mix in a few diffusers on my ceiling and perhaps behind my speakers replacing absorption panels now there. The side walls and wall behind me have good absorption. I also have floor to ceiling bass traps behind the speakers in the corners of the room.

My sound is very good, but I feel this could be a nice final room touch. Perhaps helping out things when music is played very loudly which I like to do at times.

The room is 24 feet by 18 feet with 8 foot ceilings. You can see my room as part of my virtual system.

My speakers are out 7 feet from the front wall.

Thanks for your help.