How about £10? You know.. how much you're supposed to pay for a domain.
The interesting aspect of this service is as a set of triggers. You'll find some people will immediately spot a matching domain in that list - they may not have thought of it themselves, but seeing it there triggers off the lightbulb.
Sure you can do the exact same thing with a command line whois, but then you don't get the benefit of serendipity. Someone else's list of brandable domains shows an item you weren't expecting to see, and that triggers off your own creative process into a different direction, and you find an end result you may not have arrived at without that serendipitous discovery.
You are seeing the results of someone else's creative process of discovering brandable domains. You don't have to pay for that effort, but you can be motivated by it. The $250 charge is if one of those domains is a perfect match, not for the process of finding an available perfect match and brandable domain.
The route that satisfies your expenditure expectations is watching expired domains lists - that's another source of someone else's creative inspiration. But you either have to scan tens of thousands of junk entries, or have a keyword list of some sort to focus on. Even then, because of the volume, you'll miss excellent domain names that are slightly outside of your current thread of ideas.
Then there's http://impossibility.org/ - generating available domains centred around a keyword. It's interesting, more serendipitous than expired lists, and purchasable immediately by registration. This is probably one of the better "suggested domain name" tools around, though it's just sticking words before or after your keyword. Sometimes an good domains does pop out, but it takes a bit of a graft, or a lazy Sunday afternoon.
Or sit there typing one domain idea at a time into a whois. It depends on your own level of innate creativity as to which approach will reap dividends. Personally, I use several different avenues. This is one more to keep an eye on.
Don't underestimate the creativity and inspiration. This is perhaps a better source of quality domains than Sedo/GoDaddy auctions, ebay/flippa/digitalpoint. Better, because of it's focus on brandable names rather than generic keywords / keyword-heavy / geo-targetted domains that are the current vogue in domainer/internet marketing circles.
These guys won't know what matches perfectly for you, only you do. If the price upsets you, you are not forced to buy even if it's a perfect match, you can just find another perfectly matching domain that is available.
The costs in terms of our time, plus the design time are going to be way more that $250 - so if this has something you want and can use, great. If not there are literally millions of other names out there.
These guys, IMHO, are adding value. If you think not - fair enough, but they aren't selling just a domain. They are selling time saved. Some peoples time won't be worth as much, some people are already talented designers. For the rest of us, this is a great idea.