As for the Dell E1705, all I can say is that, for $1600 it ought to come with a pair of socks withhandles, 'cause you're gonna bend over and grab your ankles. Integrated Intel graphics, marketting McAfee as a 'plus'... you can do better for the money.
As for buying a laptop off of eBay... You are on your own. Just try to make sure that the person you are buying from has a really good reputation.
My Rig: SABLE
Antec 300 Illusion / Antec EarthWatts EA650 650W / EVGA GTX 760 2GB
AMD FX 8320 x8 Black Edition / Gelid Tranquillo / MSI 970A-G43
Sandisk Ultra Plus 128GB / Samsung 840 120GB / WD Black 750GB / WD Green 1TB / WD Red 3TB
G.SKILL Ripjaws 2x2GB DDR3 1600 - Crucial Ballistix Tracer 2x2GB DDR3 1600
Win7 Ult 64-bit - Func MS3 Mouse - CM Storm QuickFire Rapid Mech Keyboard
R.I.P. Danny L. Trotter
... 14 Nov 1945 - 4 Sept 2009