I stopped by my local Radio Shack and they had these on clearance for about $1.50 a disc. I'm not sure if all stores have these, so YMMV. They had 2x and 4x discs that are MIJ. So I picked up a couple of each speeds to test out. The 2x discs have purple bottom and the 4x have gold bottom and yellow hub. Why did TDK switch to gold? Are the 2x that use purple dye still considered good?

I used DVDInfoPro to get media codes...
DVD-R 2x TDKG02000000
DVD-R 4x TTG01