I'm not sure if this is the same material but I've used what's called "Showerboard" to do this. It was $7 a board if I remember correctly. I put some particleboard behind and made a nice wooden frame for it.

In terms of "erasability" it's more than acceptable for the cost of it. Basically if you erase something within a few day it erases fine with minimal ghosting. If it's longer than a few days then you need to erase a little harder or use windex, which works just like the dry eraser liquid.

Having used the very expensive whiteboards at my previous job I don't see a big difference. The expensive ones still left ghosting and needed to be cleaned every week or so.

Lastly, I would experiment with markers. I've found that some (brand and color) erase better than others.

For what it cost, I definitely recommend doing this.

EDIT: Here is a picture of my whiteboard. https://app.box.com/s/jby2cznhev66ec1izvck