I'd believe the difference all right-i've used Bubble wrap for about five months, paid $20 for enough to cover every window in the house and made my money back(with interest) in a month! The fact I started with high efficiency panes in the first place didn't hurt much either...
And just for the record Redneck, I stole the idea from the same webpage:
BubbleWrap
Fantastic place isn't it? I hope to have one of the simple DIY Solar Air heaters done in a few weeks-my version will use Soda cans since my neighbors literally inhale the stuff...assuming my 50+ hour weekly schedule doesn't cause a stress induced coronary of course.
BTW, have you wrapped your water heater and pipes yet? It's another cheap mod with really good returns-I think I may have gone a touch overboard as my cylinder tank rapidly became a rectangle...
Oh, and welcome to Ecomodder!