you can be sure that oliver2002 is one of the most knowledgable persons on the forum and he understands exactly how airlines work in that respect.
the minimum bids however don't start at 1€ - airlines set the minimum and maximum bid amounts for each flight. like Keyser wrote "minimum bid" was 430€ which pretty much covers the airline costs for the business class seat (it's additional revenue).

nobody denied that, just he understood me wrong and I corrected his understanding of my msg.

Around 12 hours before the flight there were 17 seats left after my bid was accepted. The cabin had only 2 seats left by the time we took off & those 2 seats were unoccupied since they were broken so it seems like in the last 12 hours they managed to sell off all the seats either via bidding or airport upgrades.

Yes, but meeting the minimum amount

Of course. That was never in doubt. You can’t even put in a bid unless you bid the minimum amount.

How does the pricing for upgrades at check-in compare to the pricing in the online bidding process, for ITA?
does it make sense to wait for that?

Will the bid for upgrade option be immediately available after booking? I booked on the US website, if that makes a difference. I tried using the upgrade page by entering the PNR. It says the flight is not eligible and I should review the terms and conditions. It is a one-way booking in eco light, if that is relevant - MUC-FCO-TLV.

Not that it is the best indicator, but the ITA site says there are at least 8 business seats still available for sale.

I bid around 350€ (barely minimun) for an upgrade from a cheap Y ticket to Y+ JFK-FCO and got it. At check in they donwgraded me back to Y because Y+ was overbooked. The lady at check in said the usually get some no-shows and I actually got bumped up again at the gate.

AZ cannot even process the Qpoints, miles and points for their flights correctly, they mess up classes and cabins, and credit anyhing. So I wouldn't be surprised that they cannot process a simple upgrade charging your card. If I were you, I wouldn't bother after the first failed attempt.

Is there any way to bid for upgrade (or otherwise upgrade) an ITA segment booked under AF codeshare, or am I out of luck?

Last week flying YYZ-FCO:
C$660 at the airport for Y to Premium.

DEL-FCO flight next week. Booked in premium economy. I got the 'bid for upgrade' email today. Put in the minimum bid to business class, which was €370.

Last time I put in a bid that was 25% over the minimum bid amount & got the upgrade. This time I've decided to go with the minimum amount.

Cabin is over 50% empty at the moment so hopefully the lowest bid will go through.

Minimum €370 bid accepted 60 hours before flight departure.

My family of four will fly ORD-FCO as part of a United award (yay for newfound routes when ITA became available). Is bid-for-upgrade available when flying an award? The United website says our AZ leg is booked in Economy (F) class (that's funny) in case that matters.