With so many oils to choose from, between the regular shelves and the fabulous dispensaries at Alfalfa's and the Pearl Street Whole Foods, how do you choose? Obviously, it all depends on your cooking/eating propensities and what appeals to you. But in terms of figuring out what these bulk oils actually cost, Alfalfa's has an extremely helpful chart that shows approximately what several sizes of bottles will weigh when filled with oil (presumably once the tare weight of the bottle has been deducted), so you can make reasonable cost comparisons. According to the chart, a filled 500 milliliter bottle will clock in at 1.02 pounds, and a 750 milliliter one comes in right at 1.5 pounds. Doubling that 500 milliliter size, you can figure a one liter bottle weighs basically two pounds.
Everybody has their own preferences, but for me, my course of action is clear. I go through olive oil by the liter for everyday cooking (freshness being an important factor - never buy a size that will sit around for too long), so for that purpose, my choice will remain Whole Foods' own cold pressed extra virgin 365 brand off the regular shelves (I like the Italian best). It comes in one liter bottles for $8.99 each, but it looks like it's transitioning to one liter canisters at $7.99 (with a Turkish option at just $6.99). If you do the math above, filling a one liter bottle from bulk at, say, $9 a pound would run you $18 for that bottle, so buying 365 off the shelves still works for me for the oil I use in quantity. I'd turn to the bulk dispensers for special oils bought in small quantities, and for those, I think the selection at Alfalfa's has an edge (I'm currently loving their organic Tuscan herb oil), but Whole Foods tempts me too, and I'll have to try that chipotle-infused one, for sure.