
Untrimmed pork tenderloins are rather inexpensive at Costco.
There are two packages of two tenderloins per package for about $20.00. So here are eight untrimmed tenderloins for about $40.00.
EDIT: The above doesn't explain the Costco packaging well. Each Costco bundle has two packages of two tenderloins each. So you get four pork tenderloins for $20.00. The photograph has two bundles or eight separate pork tenderloins.
Brine them in a simple brine for at least a few hours.

You’ll need to spend some time suitably trimming them.
Remove all the silverskin with a
sharp knife with a point. Also, trim off any small parts that will cook faster than the main tenderloin body.

Trimmed to length. (Yeah, I added one.)

Completely trimmed.

Edible trimmings for shish kabobs.

Inedible trimmings.
Rub them with your favorite rub.

Smoke them at 250°F until the internal temperature is ~140°F. Then sear them.
Rest them for about ten minutes, slice and serve.
EDIT: When trimming, also remove as much of the thin, clear membrane as you can.