Hello and Assalamo Alaikum,
It’s always good to research before buying or selling your domains. One of the helping tool is to find out relevant past domain sales. If you are at the buying side, you will need to look at what similar domains sold for, the venue, extension, the year, etc. There could be many other factors which you can take into consideration but this is a must and you don’t end up paying more! So doing your due diligence is must.
If you are at selling side, you must look the past sales just to have an idea of not selling for less and leaving money on table. You will always be happy to get more than you expect but on the other side, if you will sell for less, that won’t be good for you and the market as well which is normally set on past and recent sales. Although there are exceptional sales every now and then.
I normally use NameBio.com which is frequently updated and gives you all the info you want related to past sales with all the search parameters you would want to have it. DnSalePrice.com and Dnpric.es are good as well but I don’t think DnSalePrice has enough and much updated sales data but still good to check out than missing out completely.
You can also watch out Domaining.com which shows you the top 500 domain sales. It was last updated on 09/12/2013 but still worth a look.
Another one is DnJournal.com operated by Ron Jackson and this is the updated on weekly basis and I really like it. This gives you lot of info of what is going on every week. Not only that, you can also find out the previous weeks, months and years sales. Hats off to Ron for updating his website every week for years with lot of sales.
Feel free to share if you are aware of some other useful websites where we can find past domain sales.