Why are pharmaceutical drugs so expensive?

The debate goes something like:

(From the left)
1. Corporate greed and irresponsibility

2. Disease mongering boosting sales (see also # 6 below)

(From the drug companies themselves)
3. Price fixing in all other world markets (try this link as well)

4. Pipeline expense and failure rate, combined with regulatory uncertainty

5. Simple economics: how can a massive research and development campaign work effectively for drugs intended for rare or short-lived diseases?

(From free-market proponents)
6. Increased demand

7. Extended monopolies on drugs

8. No competition (try this link as well)

There is certainly a kernel of truth in each of these, although #4, 5, and 8 seem the most culpable. Curiously enough, each of those three indicts the FDA in spirit as well as in letter.