I feel bad for my harsh comment...let me see if I can help...
first of all, you must assess the name from all angles and consider, not just how catchy the name may be, but who you are going to sell it to. the amount of potential buyers in the world means its likely to go quicker and for a better price. now lets look at an example...
watercooler.info...
.info is usually used for educational purposes (I doubt theres many people that want to enlighten people about water coolers). this immediately takes most of the value off. there would have been some if it was .com or .net.
who would actualluy buy this when other options are available to buy such as chillmywater.com, if I was a watercooler company I know which one id prefer. it is .com, explains the product and very brandable, and also more generic to the audience. id then create a quick logo,host the site (on existing package, not worth paying extra to do) display the logo and maybe a few affiliate links to other water cooling companies.
infact if you did all this and the logo was half decent id probably consider purchasing it myself... if only for a second.
hope this was a little more constructive, regarding valuations though I wouldnt expect any to go for more than $100, but by specifically targeting the right potential buyers who knows 2,3,7 could fetch high £xxx to low £xxxx
thanks,
System