That's the usual dynamic in Belgium.
What usually happens though, is that you determine an estimated FMV (eFMV) based on recently sold properties in the neighborhood that are similar in size. Experienced realtors are usually quite good at this. You can add a factor to the eFMV to get your list price. As a seller, in the worst case, you may have to drop your list price to your eFMV. Best case, you get a nice bonus. When there are multiple bidders around your eFMV, but under listing, you have some leverage to get a higher bid. Let's assume your eFMV is 850K. "Look, I have a bid of 850k. You're at 825k. My list price is 900K, but if you bid 875k now, it's yours guaranteed." It looks like a steal in the buyers eyes ("25k below list price!") and you get a nice 25k bonus over the eFMV.
As a buyer, this silent "list price is always accepted" rule, gives you the ability to properly filter properties because the list price functions as a cap. This saves both buyer and seller time because you're not chasing unreachable properties. You can also get a realtor to get your own estimated FMV for the property that looks interesting. It's up to you to decide if the certainty of the buy is worth the difference between list price and your eFMV. If not, you can always bid something lower, closer to your eFMV but with the possibility that someone outbids you.
The process usually is really fast, because realtors are good at estimating a FMV, most sellers realize they shouldn't expect a huge premium over that estimate and buyers accept a premium for the certainty of an immediate sale.
If McDonalds has their BigMac Meal labeled with CHF 12.50 (the current price in Switzerland IIRC) the cashier won't be able to refuse to sell it to me for that price even if I look particularly hungry and it's 4 O'Clock in the morning (and might thus be ready to pay more than 12.50). At least in Switzerland you are generally obliged to honor your displayed prices.
I have never bought a home (I'm a 23 y/o student), and I don't know if the process in the US would be comparable to the process in CH, but if a home is labeled with a price of say CHF 1'250'000 I expect to be able to walk in there with a bag with 1'250 CHF 1000 bills and pay for the house without additional price haggling. However I can imagine that this is not how it works (apart form the "pay with cash" part, which I know works for sure).
If the average market price for my neighborhood raises after my listing, am I not permitted to raise the price? How would you apply this reasoning to a stock market?
You're attacking basic supply and demand here. Let's say I set a list price and then figure out I could have asked for more...you want to legally bind me to sell for less than what the free market is willing to offer? Where does this stop? Should we ban speculative investments as a whole?