Sales numbers is NOT nearly as important as REQUESTS/OFFERS to buy.
If you have a 100 domains and get NO requests to purchase or all purchase offers are like $20 from India, then something is wrong with your portfolio.
So if you tell me you have 10 requests/offers per month, then you asking price is too high.
Sales in general is a numbers game, get in front of enough customers and you will make a sale.
Afternic/Godaddy ACTUALLY gets customers to see your names. Uniregistry/BrandBucket DO NOT get customers to visit your names. Both of those companies use Direct Navigation to do sales. Not enough searching on their home page websites to make it worth while.
DNSales does add credibility with a phone and actual people to talk to and there sales people overall do a nice job! For DNSales/Uniregistry I grade a B- if there commission rate was 12% I would give it a A-
SIDE NOTE: Remember all brokers don't get paid until you agree to sell, SO THERE real job isn't to maximize your sale. There REAL JOB is to talk you in to accepting the offer they have in hand so they make there commission.
Do you buy advertising on Google.com or Ask.com? If your answer is Ask.com, everyone knows why no one is buying your domains
(NOTE: Attempt at humor)
So using Afternic with BIN pricing and instant transfer gets your domains the most exposure. If you are worried about missing one big sale with BIN pricing ... then why did you ask your question?
Without seeing the portfolio and how bad off (AKA crappy it is) there is no way to give you a exact answer. NOT TRYING TO BE MEAN just factual.
If the domains are like any of the 100 spam emails I see each day in my inbox offering to sell me really crappy domains, you know you answer.