Firstly: You do realise there are no cables, earth clamp or rod holder with it, at least it appears there isn't.
The positives are it's cheap and you have good support from Paypal initially, down the line if it packs in then that support may not help with an awkward seller.
I always view stuff like that as a bit risky but a bargain if it all works out ok and continues to do so.
Are there any leads with it?, I can see the power lead only?
Clamps, cable and rod holders are all on ebay and not too expensive.
Is it worth a punt? depends how much £85 is worth to you, although you could be cheeky and offer £70 and see what they counter offer with, it will probably be £80.
There are thousands of similar cheap Chinese machines in use, they do have a higher fail and dead on arrival rate than the more expensive machines so it's pot luck really.
If it's faulty or breaks when you give it the first day of heavy welding ..which you should do then just follow ebays complaints procedure and your money is safe.
Don't place any value on that with ebay sellers, they can close accounts and reopen under another guise several times a year.Comes with 1year warranty, for what it's worth.
What about just live & neutral supply, no earth??
What exactly are we expecting for £85?