Oh wow I could write a book in response to that type of question.
"if you were the seller in that transaction, is the opportunity cost of waiting a bigger worry than getting the best price?"
If I understand what you are asking about the downside risk of not taking an offer on the table? That is always a consideration in any transaction where you are selling whether it be real estate or another asset. And it depends on a multitude of factors.
Well first let me tell you that in any situation like this you are in a sense playing the person that is working for you many times (the broker). They have to be convinced by you not told by you. They have to believe what you are telling them in order to do the job for you. And they are playing you as well. You are an actor playing a role. It is a game. This is the game that I play (I don't play any other game by the way and I have never played a single video game either but I like this game..)
So you have to decide what your position is and them somehow convince them of that so that they act in your best interest. This means being neither to honest or to dishonest.
Each situation is different and it is really hard to generalize. In one case I was negotiating a lease and I told the broker "I will take $x per sf however if you can get me $x * 1.1 per sf you have really done a good job!" (arbitrary figures btw). All the while I knew he would be able to get me the 1.1x and maybe more. (And he did..) I had already figured that out in advance of saying that. So I was playing him so he would feel like "Daddy is happy". (We can call that the "please Daddy" routine). In other cases I might have said "I need $x * 1.2 at the minimum, see what you can do for me".
In another case I find out that a broker had gotten me a good deal by making my offer on a property "as is". I never told him that of course. But that is how he got me such a good deal. Most people would have scolded the realtor and gotten pissed off. I didn't. In fact I was willing to even waive that mistake on his part (if you want to call it that). When I found out, I wrote him an email and made a joke and said "wow funny I didn't know I was buying that "as is"!!! He writes back and says "that is what I needed to get him to accept your lowball offer!" (was about 32% off asking price..). Then he tells me he can take the repairs out of his commission (I didn't even have to ask). Of course I could easily back out of the deal if I wanted. But I was actually willing to even pay for the repairs that I hadn't agreed to. Not because I got such a good deal but because I want him to take risk for me and not feel like I am some little old lady that will take him out to the woodshed if he fucks up. In other words I want him to feel as if in the end he can take chances if he needs to. This works because that way I get an out and he takes the risks. If he had asked me upfront "I will need to make the offer 'as is'" I'd have to agree to that and then I couldn't back out as easily!.
Here is a real life situation re: quick sale vs. wait.
I had a commercial rental property. It was vacant (for about 5 months let's say). One day there is a flood in the complex and another owner calls and wants to know if I can "help him out" (was a Physician). Almost like he thought I would let him use it for free? Anyway I tell him that his insurance company will pay for everything and I will deal with the insurance company. The insurance company tells me that the Dr's unit should be repaired in 4 or 5 months so what will it cost to rent it for the 4 or 5 months? I say "can't do that I need at least a year's rent for the 4 or 5 months" (and why). We go back and forth and in the end I get the insurance company to agree to pay me for a year rent (full ask) for 4 or 5 months. That's full ask rent. But in the end I didn't even rent to them. I was worried about tying up the property for those 4 or 5 months because a realtor was telling me he had other interest in the property from people who would take long leases. So I had a choice to make door number 1 or door number two. How do you know the right thing to do? You don't. You use all of the info that you have and your experience and you make a decision. Sure bet, 1 year rent for 5 months occupancy or door number two longer lease. MAYBE MAYBE NOT. Of course having 7 months to find a new tenant seems like a good idea also, right? I decided to go for door number two. And I did find a tenant and they now have a 2 year lease with options up to 8 years and also an option to buy the unit. And they have renovated the unit at their expense. [1]
Does this mean I am right? Well in this case I was right. I took a chance when the safer bet might have been to take the 1 year lease where occupancy was only for 5 months. This type of thing happens frequently it's never like the case studies and so on.
[1] And in the true spirit another thing happened on this deal. I find out that I am not only paying my realtor a commission but also paying 1/2 of that to the realtor that brought the deal to him. Did I freak out? No, who cares so I paid an extra 3%. The guy who got the 3% convinced his client to go for the full ask rent so he deserves to make 3% and not 6% on this deal. (Rent % is sliding scale on years so these are not exact numbers just making it easy for the purpose of a comment..) And I cut the check right away for the commission so he got it the same week.