Bob Jackson writes:

My question is this: can anyone speak to their claim about the $49 just
being a way for companies to get their foot in the garage door (pun
intended)?

Bogus sales trick. Similar to a bait-and-switch scam. Suckers those
needing a repair who hope against hope it will just cost $49 to fix their
trouble, because, hey, a "tune up" (meaningless term in this context) will
do the job.

The most critical sales edge is just to get the customer to call. Hardly
anyone turns away whoever shows up first, because they have no idea what
they need. If somehow they know what they need, they still have no idea
what it should cost.

Your only defense is to know how these door work, how they fail, how they
are repaired, and what the market prices ought to be. Anything less sets
you up to be a victim. Even "reputable" firms will exploit your wallet.

Information asymmetry.