Im interested in buying a phone from ebay but the seller has many of these phones. i want to buy five of them.

well the seller has over 50 feedback and has 30 phones as a quantity. he says that the phones cost him about 200 from a wholesaler but in actual fact they are going for 300 on ebay. could this be true? it is a nokia n95 by the way. if i were to pay him via paypal without using ebay have i got any security or promise that i will get the phones? if i do buy and dont receive the phones what can i do?