You can try the Nikon's for double-elements. I'm not sure if they have it in 72mm size though.
Hoya, I know, has 72mm close-up filters. Not cheap though..
Are you using a Panasonic FZ-10 or FZ-20 camera?
If so, get the Phayee or Raynox (Yoshida) adaptor. They allow stepping down to 62mm and 55mm respectively. Hence, you can use smaller (cheaper) filters.
Nikon 6T's are double-element, 62mm filters. Their 5T are 55mm filters, IIRC.