Am i obliged to buy when seller refused at first..

Not sure about that john. A contract is a contract is a contract. Oral, written or otherwise. Now proving it is another matter. Audiogon Should get right on top of this, because this is clearly a "bug" in their system that undermines the formal more profitable for them system that they have tried to establish. One of the motivations to stay within that system is that it is supposed to provide at least some protectton to buyers and sellers from someone who is negotiating in bad faith. The ability to refuse an offer rather than decline it, while leaving the buyer on the hook will drive buyers away. Without buyers there will be no sales. Without sales no sales charge and eventually no sellers.

Based on the rules/policies that govern trading at this site, when a prospective buyer makes an offer to purchase an item, the seller can select one of three actions pertaining to that offer,
1. Accept,
2. Decline, or
3. Counter.
Selecting one of these three actions triggers a specific outcome. However, the actions must be selected by using the tabs shown on the listing page, as there are no provisions for actions to be triggered by sending a message to the prospective buyer. In the event the seller does not select an action, then the offer expires after 48 hours. In this case, if the seller did not specifically select the action to "decline" the offer then, based on the buy/sell rules of this site, the offer would have remained active for 48 hours, during which time the seller could have still accepted the offer. The message discussed by the OP is not an accepted mechanism to decline the offer, based on the posted site buy/sell rules.

I agree with most here that, assuming the OP’s story is factual, then the seller displayed incredibly poor form. However, it may be good to remember we have not seen the message from the seller, or heard both sides. At a minimum, this situation is a good reminder of the importance of knowing the rules, which can be found by selecting "sell" at the bottom of the homepage. Unfortunately, you will need to follow a couple of additional links to see all of the information.

Again, there are 2 sides to this story. Provided the information we have to work with is factual, it seems an error was made by the buyer in not following the correct AG protocol, the seller proved to be not the sort we would wish to deal with (being kind here), and AG probably should assist the buyer and themselves by removing the feedback. I always communicate with buyers and sellers via AG such that a record is maintained there.

I have sent multiple emails to Agon and never received any reply back. I will send one more today. I don't care about $19 fees but neutral feedback erased by 100% positive feedback :(

A rejection made in writing is a rejection. If it's in writing it's not "off the record". The written rejection of an offer ends the offeror's legal obligations, even if the seller did not hit the reject button. The offeror (buyer) is entitled to reasonably rely on the written communication by the seller rejecting the offer.