No. The PayPal chargeback could occur tomorrow, or 6 months from now.
That is a scam.. Pure and simple.
As an ebay seller myself, with several powerseller accounts, I strongly advise you to not take part in this.. You'll regret it - believe me!
The money will be available to take out to your bank, whether it's funded with a fraudulent card transaction, but PayPal will come back to you later and freeze your account, plus you'll have to pay them £12.00 (or the equivalent in $$) for the chargeback.
You can take the chance if you wish... but it stinks to high heaven!