Well for about $200 you can make 4 bass traps for the corners. Then you could maybe use some Ultra-touch and make some absorber panels for about $40 for 6 panels. None of that's including wood to build frames.
There's plenty of builds on here you can check out. Find my "Ultra-touch" thread and arcadeko has a few threads on his builds you can check out too.
I haven't made anymore besides that one panel I did for the thread. I can't seem to find anyway of getting anything r13 or over shipped to me at any decent rates (i want to use it for bass traps), most suppliers seem to be in the N.East and out West. And I already have 6 rockwool panels that are in my room so no real point of making more right now , its hanging long ways behind my monitors right now, I can definitely tell a difference sitting at my desk, but haven't done any actual measurements. I was looking at that as a cheap alternative to do bass traps, but the R8 works great for doing your standard panels, it was easy enough to work with and is $6 per piece, and you can get that from HomeDepot online if they don't have it in store.
The idea with the r13 and up is they are bigger pieces. The r8 is 16"x48", then the r13 and up is 24"x96" so you basically two panels for one once you cut it.
I'd still recommend getting it though if you can find some and give it a try.
Nope apparently not. I spent almost 2 hours there a few weeks ago with customer service and one of the "department specialist" (don't know what you would call them) trying to figure out if there was some way to order it. Still don't understand why they can't
Well there is the fact that HD purchases in bulk to get their pricing. They sell tile made by Daltile, cheaper than the actual outlets of the company can get it for themselves. If it not in their purchase contracts, it just not happening.