It's $40 at the DMV for a lost title search, and if they can't find one, they will create one.
Then, there's 0 hassle in selling it or proving ownership to register it.
And, it needs to be done by the LAST title holder. so if this guy sells to you, you have no idea who owned it before him and have no one to contact about getting the title. it's a total hassel for such a small fee.
It's pure laziness on the sellers behalf and i would never buy a car like that unless it was for parts then junk.