How much does your most expensive bottle of nectar cost? Do you have the recipe for it? I've heard that if you place it into the basement and leave it there for several generations, the value might increase up to §10000.

A recipe of 9 life fruit and 1 pomegranate is supposed to give the highest base value, moreso if you upgrade the nectar machines and have all processes available:

If you're after a high-value batch: Improved Pressing and Extended Nectaration. A 9 life fruit/1 pomegranate recipe will net 5 bottles at 523 simoleons each (batch value: 2615).

If you're after a high-value bottle: Flavor Enhancement and Concentrated. Same recipe, 3 bottles at 653 simoleons each (batch value: 1959).

(Info from this website.)

for the highest base value you should use 90% of life fruit and 10% pomegranate but with aging (best to leave it in a basements for few generations) the value might bump up to §20000 at least this happened in my game. the most expensive nectar (with the recipe i already mentioned) in my game had a price of §16000 after 33 weeks.
check the following forum people there have made nectars that were valued at §100k or more!
http://www.carls-sims-3-guide.com/f...php?topic=880.0
it looks like you can also get bottles from transfigurations that are worth more than §300k but i never tried this myself.

Thank you for answers, both of you were very helpful!

I gotta try some of those recipes, but I've been hesitant because Pinstar's rules say not to use or grow any Life Fruit. But as long as I keep my Sims from drinking it should be fine.

$1,259 - 55% Gralladina, 44% Pomegranate, 1% ? - This is my highest-valued nectar at 34 Years.
$522 - 90% Flame Fruit, 10% Gralladina - This is my highest-valued homemade nectar at 14 Weeks.