The Denon POA-8300 and POA-8200 come from a set that Denon sold in the late 90's. At the time they where Denon's flagship home theater components. The 8200 is a dual mono THX certified amplifier and the 8300 is a triple mono THX certified amplifier. Each is rated 120 watts per channel, which is a tad underrated. They where to be used in conjuction with the AVP-8000 Dolby Digital preamp/processor.
The POA-8200 can sell for around $200-300 depending on the condition.
The POA-8300 can sell for around $250-350 depending on the condition.