If I read the LIFETIME warranty correctly, and they are nearly identical
for most all manufacturers of regulators and BCs, manufacturers guarantee
original owners that should their regulator or BC fail they will pay for
all replacement parts, and some warranties include labor too.

This warranty does not, however, guarantee that the regulator or BC will
function properly at depth each time its used, just that if it fails
they'll pay for repairs.

Is this correct?

In such a case, the cost of parts seems trivial, as you could be dead or
severely injured.

I bring this up to discuss the value of buying second hand regulators and
BCs or from unauthorized dealers like, LP.

In speaking to dive shops, the rebuild kits typically run $50, =/-
$20.  Dive shops typically charge 0.5-3x LP's prices for new equipment, so
in the end, a $300 regulator from LP sold for $450-900 pays for itself in
the range between 2-20 years*, depending on your final cost and cost of
maintenance.  You get the best bang for your buck the greater the
difference between LP prices and the purchase price.

I tried locating a thread on this and couldn't find one; so soliciting

[* at worse case, the savings for regulator purchased from LP is $450-300 =
$150, divided by worse case dive parts at $70= 2 years worth of
parts.  Best case, savings is $900-300=$600, divided by best case dive
parts = $30, 600/30 = 20 years.]

Warm regards,