How did you find one to register if they are all taken?
Honestly though .. if you need to ask if you should get it .. then you probably should not. The only reason to buy a 5L.cc as a reseller is if you're going to resell it to the Chinese market. Something I've never done .. and who knows what the current liquid price is. You need to be able to answer that question before even considering buying such a domain.
Why are you specifically looking for a 5L .cc?
(Particularly when you don't seem to know enough about the market that you actually need to ask if you should buy it!)