Price check: Letus B4 Compact Relay
 

I picked up a Letus B4 Compact Relay with my secondhand Letus Extreme, and don't currently have a use for it. I might keep it for future use, but I'm wondering how much these fetch second-hand right now? I can't find any completed for sale threads on any forum or ebay. It looks to be in excellent condition. It one of these:

Creative Video Letus35 LTB4S Compact B4 relay (F1.8) - Allows direct fitment of Extreme / Elite / Ultimate to B4 mount cameras

Letus 2/3" B4 Compact Relay Lens - Zacuto