That's the case
Then my advice is to be suspicious and cautious. The LiPo batteries s/he is selling might very well be in good condition, but how can you tell before you buy?
As a side note, it is not
that difficult to deplete a LiPo all the way (thus doing damage to it), but it is easily
preventable. I had an LVC on my LiPo battery and when it beeped, I recharged my battery and found that it was depleted almost 90%!
This means that even though I couldn't squeeze out that extra 9 or 10%, LiPo batteries can really give you a lot of "maximum thrust" with a nice amount of room for error compared to NiMH or *shudder*, NiiiiCaaaad
EDIT: Depending on the cost, and the type of chargers, it might
be worth the risk if the chargers themselves are good ones (Make sure they're LiPo chargers with balancing ports and whatnot).