Air is definitely overpriced, as everything in this sport is. Angel air regs are dear, but your paying for the electronics. If you dont want an all singing all dancing setup, then buy cheaper.
Bottles should definitly be cheaper, but remember it's this country that takes a fair chunk of money off us in tax and import duty. Just look at the prices in America, same bottles, maybe tested to DOT standard, but the same bottles.
When it comes down to the base line, this country is getting to be too expensive to run, and we're paying for it.