Are you comparing Sig P320 Spectre Comp prices among online FFL dealers and local shops?
Here are some street prices:
P320 Spectre Comp Price Comparisons
Most prices listed are fairly similar distributors are
Guns.com - $859.99 (X Carry)
Brownells.com - $1399.99
Primary Arms - Not In Stock
Palmetto State Armory - Out of Stock
Budsgunshop.com - OUT OF STOCK
Gunbrokers.com - $1899.99
BassPro.com - Out Of Stock
Cabelas.com - Out Of Stock
Gunbuyer.com - Not In Stock
Grabagun.com - $2099.99
By the way you can build a compensated P320 from scratch.
Make sure to buy the Sig P320 FCU first.
Once you have this, then you can build a custom P320 anyway you want.
The Sig FCU (Fire Control Unit) is the serialized part that requires an FFL background check.
Every other component can be bought elsewhere legally including some very slick aftermarket slides, grip modules, and barrels.