I notice a lot of reviewers buy the sample piece

They often use that as the ultimate endorsement. I have read in many places that they get a great price, but there is a time limit before they can sell. 

The reviewers get an "endorsement" discount. I feel confident that it is at a cost or below price.

Industry accommodation pricing, which is below dealer cost (dealer cost typically is 60% of msrp). 

Includes a a commitment to keep the gear for a period of time, at least a year. Some gear is shipped to reviewers under extended loan. 

Not it all reviewers are Boy Scouts, though.

Buying the gear is a critical endorsement-.ie, putting your money where your mouth is, but it's not entirely genuine. The phono cartridge which just got a rave may cost you $5000 but it might cost the reviewer $2000.