I have never bought brand new. I let someone else take the initial depreciation hit and accept that there's more risk buying used. However, Evo2700 is correct regarding the extra fees some dealers try to impose. Negotiate based on an "out the door" price so you can compare apples to apples.
2011 Rockwood Signature Ultra Lite 8293SS, 12K Equal-i-zer
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73
2010 Rockwood Roo 23SS (2012 - 2014)
2009 Ford F-150 XLT SuperCrew, 5.4L, 4x4, 5'6" bed (2012 - 2016)