Looking to purchase black Railmaster (non-LE) on strap

Hi, I've got a friend looking for the black Railmaster on strap (220.12.40.20.01.001). My first Omega dealer lost their AD status, last Omega I got was from Continental (RIP), so I'm looking for any dealer recommendations to purchase with warranty at a discount. Please PM me if you have any good dealer recommendations; my friend and I are calling around now but there's a lot of ADs out there. Thanks!

Edited to add: any idea what % discount is considered reasonable for this reference?