Muleskinner
Ultimate Member
LPK for less than the Glock Store...
https://www.21sportsapparel.com/product-page/glock-43-9mm-lower-parts-kit
and Grey Ghost Precision sells the slides directly too...
http://www.greyghostprecision.com/product-p/ggp-spg43.htm
$300 is for a bare slide. Glock store had complete factory G43 slides for $400 ready for shooting. I'm not into high dollar custom jobs .