It seems there are a lot of people confused about the value of their domains. While it is not always clear why some domains sell for a lot of and others do not. Simple theory states that generic domain names get a lot of type-ins. so for example hotels.com come gets a fair amount of traffic related to the keyword hotels. Buying those keywords on Google probbaly costs millions of dollar a year which is how the price of a generic domain is calculated.

Now lets take domain name easyhotels123.com as you can probably guess that name has no traffic which means it has no value other then being pretty which is also questionable.

hint: when buying a domain research it first using Google keyword tool to see how much traffic it is getting. https://adwords.google.com/select/KeywordToolExternal

so in conclusion buying a domain simply because it looks good is a risky take, those domains are also difficult to appraise.

good luck.

I suppose that everyone have own rules and strategy regarding that and that is the best way to go actually. Tools are good but your own opinion and feelings about certain domain name are much more important thing.