It seems as if you haven’t done this before, and (like many of your posts) are attempting to make something simple into something apparently prohibitively complex and expensive.
Lots of options out there:
Again, shouldered prefits which require nothing more than a $75-100 action wrench and a $80-100 barrel vise can be installed like screwing in a lightbulb. Under $200 as a one time cost and a bit of high torque grease, done in an hour, and no cost for future barrels.
Nutted prefits can be installed with the same barrel vise and a $40 barrel nut wrench, and a headspace gauge can be rented for $35. Under $200 with most of it as one time cost, $35 per new barrel thereafter, and again, done in an hour. A lot of guys use sized brass or factory ammo to set their headspace instead of renting gauges.
Short chambered barrels aren’t as popular as they once were, but reamer rentals are $40, and pull through kits are pretty cheap (sometimes available for rent), again, renting the gauges and using the same wrench and vise mentioned above - $300 with $200 as one time costs, and only the reamer and gauge rentals recurring for future installs.
And of course, as mentioned above, a gunsmith will typically charge around $300-400 for threading, chambering, and muzzle threading a contoured blank.