Had another chat on price negotiations, if anyone is interested. The FAQ is silent on this issue of continuing price negotiations after 3 attempts if no offer is accepted.
11:51:10 AM) Me: I understand that I can make 1 offer and 2 counteroffers to the seller. After I have used this, is there a time limit when I can resume price negotiations?
(11:56:02 AM) Mia: After the 24 hours period expires, you will be able to make a new offer on the same item again ( but it will be a new negotiation).
(11:56:37 AM) Me: what does it mean - a new negotiation please?
(11:57:04 AM) Mia: That you would be able to make an offer on this item once again

(11:58:53 AM) Me: let's say, I have made a 3rd price offer to the seller, and he has made a 3rd counteroffer to me. the 24 hours have expired. by the rules, I should not be able to make a 4rth offer. what do I do if i want to continue?
(12:05:36 PM) Mia: I understand, then you can make a new negotiations by clicking on the product page "Make me an offer"
(12:05:41 PM) Mia: there is no limit to that
(12:06:33 PM) Me: after I did not accepted the sellers 3rd counteroffer, do I have to wait 7 days before resuming?
(12:07:11 PM) Mia: No, you do not have to wait
(12:07:48 PM) Me: does it mean that I can also counteroffer the sellers 3rd counteroffer?
(12:09:56 PM) Mia: After the first negotiation has been made ( 1 offer and 2 counteroffers and they were refused by the seller) then this whole negotiation expires.
(12:10:13 PM) Mia: You can not continue this negotiation.
(12:11:13 PM) Mia: But you can make a new negotiation ( again 1 offer and 2 counteroffers) on the same item
(12:11:59 PM) Me: can I make a new negotiation within 24 hours since the last counteroffer was not accepted?
(12:14:16 PM) Mia: Yes
That means, you can actually continue by clicking on 'Make me an offer'.