Anything I need to watch out for when considering buying a used chiller?

[MTWiley]

I found a listing on craigslist for a chiller that's the same size as what I've been looking for, he says that his tank cracked ad that's why he's selling it. He's also selling the cracked tank for use with reptiles or the like so I'm inclined to believe him. It's the right size for my aquarium and I needed to buy one in the near future anyways so it seems like it might just work out. Is there anything that I need to watch out for when buying a used chiller? He says it's a year old, but looks brand new. Sorry if this seems like a stupid question, I've never owned a chiller so I don't really know the life expectancy for one, or what might be signs that I'd be better off buying something else.

I'm setting up a 150 gallon mixed reef tank w/ a 60 gallon sump, he's selling a JBJ 1/4 HP Chiller which according to their sizer is just about right for my tank. Do you guys have any other thoughts or suggestions?