Do a search as the topic of TDK media awhile back as this has been covered in detail.
In short, it depends what you bought. If it says "Certified Plus" then you're rockin' as they are real TDK media made in Georgia. If it says "100% Certified" then it's made by RITEK which makes scary stuff.
However, a TDK rep commented about TDK subcontracting RITEK of Taiwan to make their CDRs to a much higher quality of what they were accustomed to making, so to speak. If so then they are probably okay.
It really only matters to you. You got a good deal money wise. As long as you have a decent burner and software you should burn fine. If the data stays true and uncorrupted over time and you have compatibility with every reader you come across then you are in good shape.
Tip: download one of the many cd identifier programs over at
www.cdmediaworld.com
to see who makes your TDK's.
Good luck.