any cc are cheaper than her balance are fraud & scam.
no one truly know how much balance in the cc information because you are not owner the bank or have a such tool to check the balance.
only it's possible to know the balance when you breach a bank or website database when you dump the database it's maybe a chance to see how much exactly in it.
also if you have a fullz info about the cc it's have some method to check the balance again.
so final word is when anyone or someone tell you a cc with balance its scam 100%. because we talk about a cc it's not something like money service (Paypal, Payonner, Stripe, etc).
for buying cc you can visit the verified seller section.
again don't trust the balance if the cc is not fullz (fullz mean entire information about the cc & owner of the cc)