For reasons that I won't bore you with - what is the lightest bar+line setup off the shelf?Bonus question if you're really nerdy or have investigated this for some random reason, what is the most optimal cost-weight comparison (ie, dollars per gram)?

Carbon foil racing bars - if your not competing- it doesn't really matter..

What concerns most people about bars is stregth and durability.
Will it snap at the worst possible time ?
A sponsored rider pimping the lightest possible bar, is not going to use it year after year.. like average kiters.

Fairly random question in deed. SaveTheWhales gave you an excellent answer.

Since I travel a fair bit with my kite gear, I weighted all my kite gear bit by bit over the years which really helps deciding what you can bring within the airline weight limits. I stopped weighing bars as I realised they were all weighing about 1kg across many different brands. You might get a few hundred grams difference between brands / models / years but why would that matter ?

Boardriding Maui's CCS is super light given it's a very stripped down bar - great for surfing/foiling

Kauper XT - Pintxo bar looks very light too (never tried it however...)

This gear could be nice. Have to really be wanting to spend the money though.

SK Shapes - Swiss company, complete bar without flying lines 325g

www.skshapes.com/products/kite-bars/unique-bar/

That Infexion quick release is impressive.

Looks like a much better solution than the Wichard type snap shackles if you're wanting to get rid of your chicken loop.

Check out Kiss bars.
carbon, super minimal and customizationable...haha
I havent seen one in the flesh, but look the goods for light weight