Using these doesn't seem like a great deal at first, but unlike the Blue Reagent upgrade, you have chances to gain multiple products at higher skill levels.

I combined 36 Time Elixirs and 18 tears, for a total market value of about 2.65 million; 288 minutes total buff time, 7875 silver/minute before tear costs, 9188 after.

At Artisan 2 processing, combining resulted in 31 Party Elixirs, rather than the expected 18. 465 minutes total buff time, 5700 silver/minute total cost. Accounting for a lucky streak towards the end, I think the actual rate might've been closer to around 50%, which would've been 27 elixirs instead of 32, which would've still been well worth the cost.

Had +2 and +11% success rate, if it matters. No idea if it applies to critical success rates.

This only applies if you're using the elixirs yourself, though; the party elixirs have similar or lower market value than their non-party versions, for some reason.

SUMMARY: Using Aal's Tears to upgrade blue tier elixirs seems to be worth it, assuming you plan to use them. The Blue Reagent recipe is too lossy and costly to be worth it, so don't bother upgrading green tier elixirs unless you value the convenience.