A quote is just a price. Like if you send a meat wholesaler a telegram asking what the price of pork is, and they send back "this kind of pork is $xxx, that kind of pork is $yyy", then that's a quote; it's not an offer. You can't accept a quote in contract law.
The difference can be fairly fine. You can even explicitly say that what you're writing is a quote and still end up having a court interpret it as an offer.
Compare these two:
The GP’s line of reasoning leads to an implication that it could be a contract and therefor are unable to deny sale. Or reverse, a quote is a price tag not a contract.
I’d say no they’re able to deny service despite the price list.
The legal fiction goes that you take your goods to the checkout, and the offer occurs when the checkout clerk says "that'll be $19.95", and the acceptance when you offer payment.
Alternatively, you could take the goods to the checkout and say "I know it says $19.95, but this is shopworn and I'll only pay $15 for it" - which is then the offer - and the acceptance occurs when the manager agrees to that price.
