Your bank (assuming that you are organizing a mortgage via the bank) will value the property using their systems (location, age, etc.) and tell you what they think the value of the property is, and more importantly that they will only finance based on this valuation. That should give you a baseline to work with. From there you will need to decide how much it is worth to you.
Yes, indeed, i take this as an auction but without any transparency, so to say. The one who gives the higher price is the winner. However, you dont know what the others offered.
If there is only one round, do as others say, bid what you think the house is worth and what you can afford and the bank will agree to finance. And if someone else bids higher, oh well - it wasn't meant to be.
If there are to be multiple rounds, that is, after the first round the X highest bidders are invited to bid again, your strategy gets a tad trickier. You want to bid high enough to make the cut to the next round, but not so high that you cannot raise your offer in the next round.
So one option would be to bid 90-95% of your final price, then be prepared to go up the other 5% the next round. But again, you risk not making the first cut.
Alternatively, bid your final price at round one, and stick to it at round two. Chances are you might lose... but if you bid higher than you can comfortably afford you lose anyway.
Do not, under any circumstances, get caught up in the emotion of bidding rounds and be tempted to offer more than your researched price. Be prepared to walk away.
A question I always ask myself when I run into a blind bid sale is: Do I really want to buy this way? I find the intransparency problematic, given that I have seen so much shady behaviour from agents even in transparent negotiations. Unless the house was unquestionably 'the one', I wouldn't consider getting into a blind bid sale.
I won't go near properties being sold this way. Fortunately this approach of selling to the highest bidder is not the norm.
Is there any indication of the appraised value? Sometimes this will be advertised, as a guideline.
As others have said, you can and should only offer what you can afford. There may be someone with deeper pockets who does not need to rely on bank financing and can pay more.
You will need nerves of steel for this process. Good luck.
The problem with the auction system, from a buyer's perspective, is that you're highly
unlikely to underpay. If anything you'll overpay. Blind auctions even exacerbate this problem.
Once you're emotionally attached ("I WANT that house!") you're on the hook. Make sure you don't bid more than 100.0%, personally I'd probably stay at around 95%.
In Zurich, for properties with any ounce of desirability, this system is often in place. Of course, it is easy to say, don't participate, but for the kind of property we were searching for, it was the way of things. In most cities outside Zurich, this probably seems a bit crazy.
In our search, which took many years, we had to do many bids like this, including a few dastardly double rounds where you second guess yourself about a million times.
We often failed by using something like the approach above... bid what we think it's worth. Then, after several years of trying, when you are tired of it all... bid too much, win it, and then wonder what you've gotten yourself into!
When demand exceeds offering on the housing market it is hard to put an actual value on an object since value is more set by how far people want to go than by purely the location, shape and materials. Some people are willing to overbid easily 10% above what they estimate the object to be worth just to be done with the hunt or since they emotionally like the object.
In towns like Amsterdam, Zürich if you are only willing to offer the banks estimate of the value you are better of not joining the bidding at all since you stand no chance of being the highest. So having enough cash yourself is very important.