Price error on a web site.. What price am I entitled to?

In California, I'm told that there's a law (probably some section in the Business & Professional Code) that requires merchants to give you the advertised price. I believe this law was passed to combat the classic "bait and switch" problem (merchant advertises one thing, draws the customer in, and then says 'Sorry, we don't have that anymore ...). I believe that other states (like New York or Illinois) may have similar statutes as well.

I don't think it would apply in your case, but the only exception to this law (that I can think of off hand) is if the advertised price is clearly a mistake. For example, a 42" plasma TV on sale for $9.99 would clearly be a mistake and a reasonable consumer should realize that the price is actually $999. A price cut of 50% on a relatively inexpensive item seems perfectly reasonable.

If Coastal Contacts won't give you the advertised $29.99 price, I'd contact your local District Attorney. Most DA offices have departments that deal with consumer protection or consumer fraud just like that.

The given price.

No. Honest mistakes are protected. So, if they had no intent to mislead you, you have no right to the lower price.

you can "request" any price you want but they do not have to accept. Unless you can prove that they intentionally enticed you to buy using false information then an advertisment is not an offer. Your request to purchase constitutes the offer and it is their choice to accept your offer or not.

I would request the sales price.