A cast DR action is not a good idea as the grain structure of the metal is all wrong at the root of the action (Junction with watertable and standing breech).

Trade actions are availible (not at the cost you mentioned however). They are not sold to the public as the makers would have no control over their assembled quallity and may be held legaly responsible if somebody injures themselves.

I have no idea what Mr Perodeau charges, however if we take your figure of $600 I would imagine that it is for re-regulating an already completed rifle. It cannot be for regulating , laying ribs ect on a new in the white gun as he would be substantially better off working for MacDonalds at the hourly rate that would represent.

Regards