Can you just overprice it and let bidders fight on lower than asking? Essentially the same thing, but with different psychology. I wonder how it would play out differently.
So as I understand it, the strategy is usually to sell the house for a much higher price than its valuation, hoping someone is really interested in the house. And as time passes, you keep lowering the price until you get a buyer.
If you're selling on your own, there's really no guidelines.
https://www.meilleursagents.com/prix-immobilier/paris-75000/
There is also an enormous subjective-experience component in how people value residential real estate, and enormous variation in details that really do matter and aren't available in real estate data aggregates (like lighting profile, and how intelligently the interior design exploits that lighting profile).
It's so far from what I'd consider reasonable based on my (obviously limited) experience, and I'm genuinely curious how the locals feel about it.
It is a given that the price will be very different depending on the state of the property, the quality of the building and its era (1900-1930 flats command significantly higher prices than 1970-1980), whether it's a narrow alley or a large boulevard, whether it has windows on only one side or both sides, whether there's a window in the kitchen and bathroom, and whether part of the building belongs to the public housing agency (among many others). After a while, you start to get a pretty good intuition of how high a property will sell above or below the average.
Another thing about subjective experience is some properties fit certain lifestyles and will be priced accordingly. A flat in the Bastille area (lots of bars, restaurants and night clubs) appeals to people who would pay for the privilege a bonus that a boring father of two (like me) wouldn't consider. Conversely, having an address in the Quartier Latin makes it easier to enter the top high schools, so tiny one-bedroom flats sell surprisingly high (and are then rented out to university students for a far lower price than the purchase price would suggest).
1) having a lower price attracts more bidders, and the bidders may go much higher than they originally planned after they see it in person.
2) having multiple potential buyers in the mix creates urgency, which drives the price up AND lets you sell faster.
3) Homes aren't free to own. Most have mortgages that you waste money on interest again each month, amongst other things (taxes). Selling fast for cheaper may not be less money in the end.
4) Homes on the market for a long time get tainted. People get worried there's a reason no one has jumped on it yet (maybe there's a sinkhole under it, or the water is bad, or some other thing you can't tell in a driveby).
Supply = Very limited.
Demand = Increased and ever increasing.
Result = $$$$$
For mainstream properties, from my experience the market is saturated with people who price above market rates and would rather wait for months than accept a significantly lower price. If you see something that you might consider buying with a 20% discount, you usually don't bother visiting the place. This likely drowns out the people who are trying to set up auctions by setting a very high ask price.
Put differently: while the specifics of this sale (price well above asking) might be impossible in France, the "sale price well above rational market price" phenomenon is really hard to quash when the market chooses to be irrational for a while.
It seems that the English auction goes much faster for the seller, whereas in the french house market, the buyer is the one having a fast process since as soon as they find a good home with a price they like, they can just decide to buy.