I think it's worth buying if you think it's catchy and the price is not too high.
From what I understand, search engines interpret "-" as they do spaces.
pet-shop.com would be the same as pet shop.com
'http://xyz-nvb.tld' would do better for the keyword 'xyz nvb' than 'http://xyznvb.tld'.
Matt Cutts had mentioned this somewhere i don't actually remember, he had said somewhat like :
'-' are the best space seperators followed by '_'. Having no spaces between two words is the worst.
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