Welcome to FlyerTalk, TBench.

I doubt there are fixed programs that lower your cost.

There's a frequent poster in the Southwest forum with the handle nsx who does something like that, except LAX-OAK, and I know from his posts that he buys these the normal way on Southwest's web site, not some fixed cost thing.

There don't seem to be that many people who do such things week-in-week-out on any one given route. So even if it were possible and allowable (per Southwest T&Cs) to do such companion pass "sharing" (which I don't know), I have my doubts that you'd find someone else who flies the exact same route at the exact same time every week of the year (who doesn't have their flights paid by their employer).