My gunsmith said he may have to cut the factory sights out of my XDm to put in my Trijicon night sights... He was able to get them out in one piece ... so I have "spares" I guess . He did say they were a huge PITA.on a dual dovetailed gun, w/ sights that are not a royal PITA to get out (xd's, kimbers) 25-35 is normal.
On guns that we are certified to work on (Glocks, S&W M&Ps), we install the sights free if they are bought from us. On sights purchased elsewhere, we charge $15.00. FWIW.