Re: Price of ceramic "fillng"
I have had all my composites redone in cerec porcelain and it costs usually (typically) around 700 - 900 NZ dollars (or more) per tooth. But because I got more than 2 done in one sitting, I got a discount on the total. I made sure I rang quite a few "cerec dentists" before I committed myself to try and get the best deal, plus a dentist experienced in replacing this particular material (which requires skill and experience).
Your dentist is a little pricey IMO. E.g. your 800 or so US dollar charge for that ceramic would be = to around 1120 or so NZD. You can always ask around (email/phone) regarding ceramic replacement costs etc.
But yeah, they are highly expensive anyway and it varies from dentist to dentist, but they can last up to a lifetime and apparently do not tend to leak out their components as much as amalgams/composites. And they are especially good for the deeper cavities and can eliminate the need for a crown. Also apparently, with cerec anyway, less tooth structure is removed and they also expand/shrink in heat/cold.
Generally a good biocompatible and mechanically strong composite is fine as long as the person tolerates the material and the cavity is not too deep/large.