It would definitely cost more today than 10-12 years ago.
Pretty much as the same as any custom rifle build
XP-100 single-shot action used with trigger linkage will run from $400-$700
Clone XP-100 action by Borden: Alpine ($1200-$1265 depending on lug)
Stock will run from $400-$700
Barrel blank of your choice
EGW 20 MOA Picatinny rail $45-$60 (Guessing here)
Holland Radial Baffle muzzle brake
Enhance your shooting experience with our top-notch radial baffle and quick discharge muzzle brakes. Explore our wide range of muzzle brakes and thread protectors for improved recoil reduction.
www.hollandguns.com
Cost of fitting, chambering, threading/timing brake, bedding, and cerakote will vary depending on the gunsmith you use