Crossfire Reality Check ...

Through the years I have had video cards die only because the fans have failed.
I now only use passive cooled/fan-less video cards.
Period!
I put a pair of ASUS EAH 4350s into my last home built and setup CrossFire between them.
There is no physical link between them.
So, I assume it is a software CrossFire connection.
The cards were inexpensive enough that I didn't question whether or not it was actually worth installing the 2 cards.
I still have no idea if it was worth doing or not.
Although, they seem to have worked just fine for me.
The heat sinks on both cards do warm up.

Now, I am beginning to look at my next build.
I am considering a pair of ATI HD 6450 based cards priced in the $50 range, again software CrossFire linked.
They are the most advanced passive cooled ATI based cards I've found so far.
Cooling should not be a concern.
I tend to go overboard in that area because of OCing, 6 HDDs, etc.

I have win7x64 and use Photoshop, Premier Pro and other graphics and video apps.
I will eventually have a second monitor connected.
The only games I play are solitaire and mahjongg.
Although, I have several combat flight sims that are not installed at the moment.
But, I could end up reinstalling them at a later date.

My questions:
Is installing 2 of these HD 6450 video cards in a CrossFire setup worth doing?

or, stated another way:
Will the Crossfire actually work and accomplish something?
and:
Is there a more cost effective way to achieve equivalent results?