I already have a couple of trades here on this forum as you can see and you can't do a chargeback with Paypal balance...
You'll be lucky get get anyone willing to sell you that kind of amount via PayPal. As is constantly said in this area of the forum, PayPal can be charged back so scamming is common place unfortunately. Usually people only deal with trusted members via PayPal. Seeing as you havent got a trust score yet it's highly unlikely anyone will come along and trade.
Good luck though