I’d hold Auba until his contract expires at this point, we need CL football and that’s more valuable than getting a 50M fee and a second rate striker who won’t get as many goals.
He’s not a perfect striker by any means but when you see how desperate our rivals are I’d hold onto him as long as we could.
It all depends on what money is there for a squad rebuild and what offer comes in.
I think an offer for Auba in the region of £75 million + would start to tip the balance... I don't think that's an unrealistic price for someone of Auba's quality in a barren market.
Arsenal don't have much money to spend and they badly need quality at CB and CM. That amount of money helps a lot with that and with FFP by shipping Auba's wages out.
A good fee for Lacazette would probably be preferable though. £50 million...