I am all good with researching the usb monitor thing and trying that... but because I have everything wired already can anyone think of a sonarX3-solution that would cost me $0??

I'm running Windows 8.1 so I'm not sure if this function works with Windows 7.
If you press the Windows key + shift, you can use the arrow keys to move what's on the main display to any other display. 

Wow!  That's really cool.  I can definitely use that in a pinch.  It's sort of a drag with the two monitors being different resolutions... it resizes the window funky when I throw it back and forth.  But still... good in a pinch.

I use a Kensington usb monitor dongle to clone the contents of my two main monitors (track view) to a smaller, lower resolution monitor sitting by my drumset and use an iPad for transport controls.
Works great and I can enable/disable the monitor with a hotkey.

Sounds great I'm sold.  Do you have a link to yours?  Would this work:
 
http://www.amazon.com/Kensington-Universal-Multi-Display-Adapter-K33974AM/dp/B00BSREURI/ref=sr_1_1?ie=UTF8&qid=1391574018&sr=8-1&keywords=Kensington+usb+monitor

Or how about this one, cheaper with good reviews, has the display link that markyzno was telling me about above:
 
http://www.amazon.com/Plugable-UGA-165-1920x1080-1600x1200-DisplayLink/dp/B004AIJE9G/ref=sr_1_1?ie=UTF8&qid=1391574136&sr=8-1

For $40 I will happily give this a try.  I can always return or sell it.  I am a little skeptical about either of these products though.... these look like they are made for someone who only has 1 or 2 monitor outputs and wants to add on and extra monitor.  In my case, I really don't need an extra output since I already have 4.  I could have 4 monitors, no problem.  My problem is that I am unable to duplicate a display of 2560x1600 onto a display of 1900x1200.  IF this box requires being set up in the "screen resolution" area of Win7, I really can't see it making a difference for this.
 
Gustabo can you elaborate on how you set up your smaller monitor?

> My problem is that I am unable to duplicate a display of 2560x1600 onto a display of 1900x1200
 
I think a direct duplicate is not possible, or you may end up displaying a portion of Sonar only. 
 
For example, one of my monitor (the 21.5" Dell) is specifically set to display 1280x720, even though the native resolution is 1920x1080. I scaled the resolution down so the smaller vst can be displayed larger when dragged into this monitor. When I drag Sonar main windows at 1920x1080 into the Dell, it's oversized (unless I double click on the Windows top pane to resize it - but then, the tracks will be reorganized).
 
If the usb/clone monitor software is able to do that, you can test the quality by doing a print screen, then crop the image of one of the 2560x1600 monitor (MS paint will do this).
 
Then do an image resize/resample down to 1900x1200 pixel (I use IrFanView) and see the quality of the image - pull this image to your third (smaller) monitor.

Matt
Sounds great I'm sold.  Do you have a link to yours?  Would this work:
 
http://www.amazon.com/Kensington-Universal-Multi-Display-Adapter-K33974AM/dp/B00BSREURI/ref=sr_1_1?ie=UTF8&qid=1391574018&sr=8-1&keywords=Kensington+usb+monitor

That's the one that I use, didn't slow my system down at all or add any latency.
Can't speak for the other one.
One thing that I like is the Kensington software/driver interface that runs in the tray that gives you a lot of options.

I fixed this by doing the one thing I knew 100% would work.... not the most cost-efficient solution.  I bought a new $1,300 30" monitor to replace the 24" monitor.  It helps that I can use the 24" monitor in another studio but still... chalk it up to money spent impressing clients who like lights and buttons and big displays.  It looks great anyway.  And duplicates my main display perfectly.