Yes, all of them do have a standard price list. And apparently they do receive them yearly for each different brands, sister brands or whatever. So far the shops that i go to, they always show me outright the lenses that i want and the prices. After that together with the frame, they will start playing with the calculators.
It's not only coating my dear. It's also the sharpness and clarity. it's very hard to go from branded ones to the cheaper lenses. Especially when you reach progressive stages, the differences are even larger. Like doctors, surgeons, the lenses they use cost even more because they need the absolute clarity.

Also each brand also has tiered lenses. So depending on your needs and how much you are willing to pay for, will have different quality.
Unfortunately you will most likely be paying for marked up prices because they need to profit as well. Unless you know someone. I know there's an optometrist here in lowyat who offers quite decent prices. The last time i went, he did show me their price list book from the suppliers. and then he will offer discounts from there.
Can be washed. I use hand soap all the time to wash. But only hand soap cause it's the mildest soap of them all. It's less harsh to the coating.

the optometrist said hand soap, and you need to bubble it up, not just pour the liquid on it directly.
Never use dishwashing soap, cause that one is super strong.

just don't use dishwashing soap la. you will destroy the coating really fast. the hazy thing doesn't really affect your eyesights. haha. I also got experience that with certain soap. But now i just use hand soap.