Has anyone bought the Psvane Acme 300B Vacuum Tube?

These are on my radar but I really know little of them. I had contact once with a fella that re-tubed his VAC Renaissance 70/70 amp with them and said they made a big difference in a good way. It would take about $4K to re-tube my amp with these. I am not in a hurry, just doing research. I can have VAC re-tube it for less than half of this. I think tubes will last a very long time in my amp, especially after I get the MK III upgrade on this amp when I take it to VAC this October. I can also get Gold Lion PX300B tubes for half of this, any one use those? I've had this amp a long time, I plan on keeping it until the grave so I want to do this right their first time even if I have to be patient and wait to afford a re tube. I am retired so disposable income is vastly reduced. I am just thankful i have so many fine audio pieces to enjoy now that I bought many years ago when I could.