With all due respect to Audiobro, if MSB is anywhere close to the Afflatus price, count me out.
"Pleasantly surprised," with regards to what this library seems to be, would for me certainly not be over $1000, probably even a few hundred shy of that. Anything higher would be pretty much exactly what I'd expect a developer to charge (prohibitively, for myself and I'm sure many others) for something this in-depth.
Given the steep decrease in prices of some very big products which are still widely bought and used in the years following their release, including some of Audiobro's, can developers realistically use such high pricetags at the outset anymore? Sure, some professionals and hobbyists with too much money on their hands may grab it no matter what, but I feel like the majority of potential buyers would just wait... but what do I know about marketing?