My name is Sergey (nick name on forum is asgo).
I am an author of upgrades for Signum (mod. PRO) and Sorex Pro (mod. Ultra).
Right at the moment the price for Signum MFD Pro upgrade ver. 4.0 with transmitter integrated into control box + wireless headphones, stock coil 12.5x9.5, is 1100 eur including shipping from Moscow.
Should currency exchange rate change, price could change accordingly. Exchange rate could be obtained here.