Dual VCF
http://www.rolandus.com/products/system-500_521/
If you had an Unicorn Account you could see a chart with the price development of this module and the average price asked for this module.
The 521 Dual VCF (voltage controlled filter) module features two separate low pass filters for modifying the timbre of audio sources. Each filter has its own dedicated controls for frequency cutoff, resonance, and a fixed high pass filter with two switchable cutoff points. Audio and CV input mixers on each channel allow the blending of multiple audio signals and modulation sources.
Found Sound Australia Pty Ltd.
110 Albert St
Brunswick East, VIC 3057
Australia

This offer was fetched from reverb.com. You cannot contact the seller via ModularGrid. You have to visit their site.
Look up onDisclaimer: Modules listed for sale on the ModularGrid Marketplace are offered explicitly by their respective owners. ModularGrid is not affiliated to the sellers and takes no legal responsibility in any transaction.
The internet is a rough place and fraudulent behavior can occur. If you are concerned about dealing with strangers consider buying your module at an authorized dealer.