The good point is when you list your domain name on those marketplaces, your domain will be listed on dofo.com (https://dofo.com), too. So if someone searches your domain name on dofo.com, he/she will know that it's for sale.
The time it takes to sell depends on the quality of your domain names and your price expectation. I'd say you have a medium portfolio, and you should expect to sell 2-3% of your portfolio each year, but as I said, it totally depends on the quality.
Sold few like that.
Listing currently another one for $10k.