Baur KG-13B grips has just 4 press buttons, difficult something will break there, and the guys who buy this expensive grip are diehard Luftwaffe planes fans, then the chance of find one for sales is small.
In Il2sturmovik ru (google Chrome translate) flea market sometimes appear L-39 grips - Russian PM-1 copy of KG-13B or VKB Gladiator KG-12A grips.
Although not good "replica" like Baur or Cheeb2006 KG-13B versions, VKB Gladiator KB-12A grip is a reasonable option for the purpose, and are several of this grips laying in simmers drawer who buy early Gunfigher for use with Warthog grip.
I suggest you put the WTB in DCS "For Sale"
https://forums.eagle.ru/forumdisplay.php?f=144And in Reddit
HOTAShttps://www.reddit.com/r/hotasGuys who may have a unused Gladiator KG12A grip hang in this places.