I am wanting to sell 3 domain names but how much do I charge and what site do I use to get a ball park figure as to how much I should sell them for? For instance if I just google a site to find out how much my domain is worth most say between 25-129 dollars. If I was to list them on sedo.com they recommend I sell them for over 300 dollars a piece? This is why I wanted to get some opinions as to which site or sites prices I should use as? Thanks in advance to any and all who take the time to look at this post and hopefully give me some input.
In my opinion, it really depends on what the domain is. Short, brandable domain names may be higher valued than longer domain names, but that would also depend on the keywords within it.
Example: Cars.com may be worth hundreds of thousands of dollars. SportsCars.com may be worth thousands of dollars, PerformanceSportsCars.com may be worth a few hundred dollars but anything longer may be worth a few dollars.
I recommend sharing the domains you actually have so we can assist you better. You could also check out Digital Point, Flippa, or continue using Sedo.
You should also check out SEOMoz, which has great tips about search engine optimization. This might help you learn more about SEO so you can eventually know a domain's SEO potential in a moment's time.
Have you considered developing the websites, or are you just selling the domains?