I say use the one your housing manufacturer recommends then you will never have to concern your self which one should I use.
Is great advice until you have housings, strobes, focus lights etc. from different manufacturers that all "need" different lubricants!
I guess how long a tube lasts is really a function of how much you dive too. A 2oz tube lasts me around 2 years, so approximately 800 dives or so.
Tribolube is significantly more expensive in Europe, and the shipping costs from the supplier are around $21-hence the $50 price tag...I am about to order some more, so have been shopping around
Saying that having one lubricant that does everything is worth the (small) expense.
I would love to have a definitive answer on what Nauticam lubricant is. I recently bought some Dow Corning 55 O ring lubricant for another purpose, and it looks like the Nauticam grease too-but is not universally compatible!