The coops in my American city are usually the more expensive option than the chain grocery stores. They pay their staff fairly (because the staff own part of the business) which is great, but saving money for the consumer they do not.
I just don’t think a coop can be cheaper than a larger corporate entity that can purchase at huge bulk discounts for their many stores. Healthier? Sure. More ethical? Sure. Similar costs or cheaper? Nah.
These type of “captchas” look at your browsing behavior. It is sort of a “trade secret” of what it looks for, but it might be screen resolution, mouse behavior, cookies, OS, time to click, etc. Anything a website has access to that would look different from a bot.