I actually emailed Taiyo Yuden USA and asked them if they have a list of authorized resellers for their DVD media. I don't think they will get back to me though; I think I sent my email to wholesale distribution sales email, although i made the subject of the email "Counterfeit Taiyo Yuden DVD media".
I remember purchasing a lot of VHS media from http://www.americanrecordablemedia.com/mediad.asp,
and noticed they sell TY DVD-+Rs, since I have used them in the past I trust them over meritline. They are cheaper than shop4tech, so I might try them. I used to fansub anime, so I purchased a lot bulk VHS back in the day.