When it comes to domain names there is no perfect answer. No domain investor can guarantee which domain from his portfolio may sell at end user pricing. It’s nearly impossible to guess. One can however liquidate all his portfolio (salable) at wholesale prices with certainty and assurance.
It is the retail domain name sales that often grab the attention. For example the top domain name sales like Voice.com leaves us thinking why an end user paid so much for it. Or for other reason there are several other domain names that often leaves us thinking about the price and domain names.
It also applies for other extension also. For example if you are following the Namepros report completed domain names thread you will notice that there are two sales which got domain investing community thinking about the price and extension. Those two domain sales were:
and

As per Joe Nichols Only 25 reported (dot biz) sales since August. Only three of those were over $1k. Dot net also sells regularly – but seeing a Geo type dot net selling for five figures is quite amazing.
I think, every domain name sale is a learning experience on how we can reevaluate our portfolio of domain names with better and optimum pricing.