Here's another resource for you when you have the time to check it out: http://www.atsacoustics.com/
 
I got 4 of their 24" x 36" x 2" panels and 1 of the 24" x 36" x 4" panel and the combination made a very big difference in the sound of my room.  The 2" panels are only $37 each so it won't break the bank.
 
I have a pretty square room of about 13x13x9 tall with my "studio" setup in the corner.  There is an open doorway in the opposite corner behind me.  I've got 2 Yamaha MSP5 monitors and a subwoofer (I think it's mAudio) and the combo sounds great and translates pretty well when I do my mixes and compare to the car and other places.
 
Anyway, here's a shot of that space where you can see two of the thinner panels and the thick panel in the corner as a trap:
 

 
Hope this info helps in some way.

VRM is really clever, but honestly, it's no silver bullet for mixing. There are no silver bullets for mixing, alas.
 
VRM looks appealing because it costs such a lot less than basic acoustic treatment, but if you're at all serious about this stuff, you'll end up being disappointed and buying proper acoustic treatment anyway, eventually. There's a lot to be said for just cutting to the chase,

A good long read and a good long think over at the GIK Acoustics website will cost you maybe 400 dollars on the first pass, but will save you a fortune on snake oil in the long term.

I say all this as a fan of VRM. It's great for what it is. Which is a band aid on a head wound. It's a very good band aid. But it doesn't really solve the problem.

Bottom line: Headphones are indispensable mix analysis tools. But they're not reference monitors. If you want mixes that translate generally, you need a monitoring environment where sound passes through air, in a reasonably predictable way. That means good enough monitors and good enough room treatment. This stuff doesn't have to cost the earth.
 

If you want to splash out on a gadget-based fix, you'd be better off with something like the KRK Ergo. But even that's nowhere near as good as buying a couple of bass traps and moving some furniture around.

Trust me, I've bought a lot of snake oil over the years :)

I would assume VRM is a good "in addition to" some basic room treatment.  I feel like I have a decent setup in my little studio thanks to some simple additions from http://www.audimutesoundproofing.com.  Those guys are great and know their stuff.
 
Despite getting the room treatment to a satisfactory level, my interest in VRM by focusrite is certainly peeked in order to "double check"... the safety net mentality.

Does anyone here know if the VRM can work directly from within Sonar (X3), or would you need to export an audio file, open it in the VRM software check it and then go back into Sonar and tweak?  Not worth it for me if I need to do the extra hoop-jumping, but certainly worth a look if I could do it from within Sonar!

If you've got no budget to work with, attention to the basics can work small miracles. Are your tweeters at ear level? Are your speakers firing down the length of the room, rather than the width? Is your listening position in an equilateral triangle with the speakers? Do you have something (anything!) acoustically absorbent at the ear level reflection points from the listening position?

I may have missed this somehow, but I don't think you've said what the dimensions of the room are...?
 

If you want to raise your monitors, instead of using books, grab yourself a few concrete paving slabs.
 
Their mass will also help to decouple the monitors from the floor

Speaking of decoupling:  In the image I posted, you can see that the speakers are raised off the desk.  This was a VERY low-budget thing, but works well.  I got some of that foam block that you use for artificial plants to stick the stems into a display.  I stacked a few of those up and used a pair of black nylon stockings to hold them together (and make them black).  This got the speakers right at the right height for my listening position, it also removed them from vibrating the "wood" of the desk and from reflecting off of its hard surface.
 
Also, you will notice that the absorption panels are right behind them at the wall reflection points so there isn't a lot of reflection interfering there either.  What you can't see is that I have the other panels on the walls behind me.  I don't know how much these are really doing, but they work great for when I'm recording into my mic - I just put it in front of the panel and I don't end up with any of the comb filtering going into the back side of the mic and it reduced how much reflection from my vocal goes back into the room to be picked up by the front of the mic.  It makes the room recording pretty dry without being completely sapped of any energy.
 
I think the fact that I have an open doorway in the opposite corner behind me helps as well.  Even though I'm in a corner, which is typically a poor position to be in, the exit point seems to help in making the room "longer" for the sound to go and not be able to come back.
 
Hope this adds something.

All the acoustic treatment advice is good, but before you tackle any of that the first step should be taking objective measurements to identify exactly where your problems lie. This'll fit right into your budget, because it costs nothing.
 
All you need is some free software called Room EQ Wizard (REW) and an omnidirectional microphone. Here's a link to the software, and here's a tutorial on using it.

Hay there Beepster.
 
I found a bargan..a office building closed down shop...all the office dividers were for the free taking.....I got about fifty....they helped me solve that boxiness in one vocal room....and if I need Isolation I have enough to do the job in the jam room...
If you look hard enough, and think outside the box, check the news papers classified/auctions and or closure sales and or out of business businesses... ...you can find these for cheep or free...
 
Just saying they may be a task to get them in...but they can help big time to do things like dampen a room, and isolate mic sound sources.
 
Sir Les