Was the frame you were looking at the 2009 or newer YFZ-450R/X Extruded Aluminum Frame or a 2004-2008 YFZ-450 Steel Frame? $240 is a steal if it was the 2009+ R or X Frame. Most of the time the aluminum frames sell for somewhere between $850 - $1,250 depending on condition and year and that's without subframe, and your looking at roughly $250-$300 on top of that for good used OE Subframe.
The 2009+ YFZ-450R and X are long travel from the the factory and they have a lot better frame and suspension geometry. The stock and aftermarket shocks they use have have a lot bigger shock bodies, shafts, resi's, and coil springs.