"What are we up to now ? $30-40,000 ?"
I don't know. But the FBI expressed they were surprised how "pure" it was and such so I got the impression it was special.
When you add in the logic of "pure" into this entire search...then you start talking of a "expert"...not a teenage kid named Carl working in his home-made lab over the garage. If you look at all of these scientists....who work on government projects...all make in excess of $80k per year. Most will make more than $100k a year...so they can afford to build a lab in the back of their garage that would easily handle this kind of situation. Don't forget...there are college labs that are selling or dumping their old hardware all the time...so a smart guy could walk in and buy a $50k item for less than $6k...and just build onto his lab piece by piece. These guys are like mechanics...they know their profession and their tools.
Behind all of this PR work of the FBI...they have to know that this is a inside job...that their list of possible performers is down to probably 15 guys...and they just can't get much further. Whoever did it...was very smart...and covered every obvious trail. They will have to slip up...and a third party realize their connection (like a ex-wife) before this will happen. In fact...they probably already know that the guy is single...because a curious wife would have called the cops already.
I don't recall the FBI ever expressing surprise about the purity. But a lot of other people were surprised by the purity because they were expecting something from some biological weapons program.
The attack anthrax didn't come from any biological weapons program. Such programs concentrate on quantity not quality/purity. They use industrialized processes where purity is a waste of time and money. Dropping a pound of powder that's only 10 percent spores on a soldier will kill him just as dead as an ounce of 100% pure spores, and the production costs are much less.
"PURE" spores come from a lab. Concentrations of pure anthrax spores are created every day suspended in liquids like distilled water so that they won't float around. It's less common to dry the spores into a powder, because dry spores will float around and are truly dangerous.