Hi Good luck in your quest they seem to be like Hens teeth 2nd hand, I have not seen a Vl300 come on the market for a long while, these seem to be long term keeper of a lathe. With the current new price of approx. 5,500 I would guess and only a guess anyone selling would be looking for 4000 plus for a near mint one and 3000 plus for a very well used / older model.
I have a VL 175 not in the same league as the VL300 but cannot fault it. Had it 10 yrs plus since buying it 2nd hand. Just prior to Covid I missed out on a 300 local to me, I looked but went to think overnight and it was gone. It was the fact the head do not swivel I was thinking on and the asking price was only just shy of the VL240 which has that facility my loss for thinking too long but the VL175 is still with me and doing all I ask of it.
With energy prices rocketing there may well be some out there thinking of selling the larger lathes so keep to eyes open but will the prices drop I am not so sure...
regards Redwill