Did the anemone ball up before vinegar dosing?
I keep a lot of anemones and once they get sick or unhappy it can take a very long time for them to return to normal, talking like 2-6 months. It's best to just keep your water parameters stable and let it recover. I wouldn't recommend trying any drastic changes as this is just going to further prolong the recovery process or even harm the anemone.
If your able to keep your water parameters stable, you can get some of the hardier anemones earlier than recommended. It's generally recommended that people wait for the tank to stabilize itself out but if you've got a pretty good solid grip/understanding on the science aspect of the hobby, people tend to and can put in anemones quite early.
As for good deals, its always hard to pass on but that's why you make friends in the hobby. Have someone with a stable tank hold it for you. If you ever plan to get another anemone, get it situated in a pvc pipe and so when its time to pick it up its easy. A lot of times, I just build rock work to hide the PVC so that when I move, which I tend to do often, I just take the pvc pipe with the anemone in it. I don't have to try to ice, peel or blow it off the rock work its hiding in.
For now, keep your water parameters stable and don't try anything new. If the condition of your anemone worsens, for example, color loss and starts to move around the tank, pull it out and read some of the guides on anemone treatments. Your anemone may already have been sick to begin with or may have gotten sick.
