Robert do you remember when we used to say the Canon EF 24-105mm f/4L IS II USM Lens (version 1 however) was the best buy in a "L" lens? I guess it still is but one reason verson 1 was such a good deal was price. I don't see than price advantage anymore. Maybe it is still out there? Anyway i used a couple of them (version 1) for years shooting weddings. Mostly on the second or third shooters cameras though.
If you go into a wedding shoot with just a Canon EF 24-105mm f/4L IS II USM Lens you are not going to get great wedding shots. Period. So, to say you would select it over another single lens is folly. You need what you need.
For instance my last wedding I used two shooters, three cameras and lenses from 16mm to 300mm. All f2.8 constant aperture, I might add.
Some people use an iphone and they think it is good! 
@ebiggs1 wrote:Robert do you remember when we used to say the Canon EF 24-105mm f/4L IS II USM Lens (version 1 however) was the best buy in a "L" lens? I guess it still is but one reason verson 1 was such a good deal was price. I don't see than price advantage anymore. Maybe it is still out there? Anyway i used a couple of them (version 1) for years shooting weddings. Mostly on the second or third shooters cameras though.
If you go into a wedding shoot with just a Canon EF 24-105mm f/4L IS II USM Lens you are not going to get great wedding shots. Period. So, to say you would select it over another single lens is folly. You need what you need.
For instance my last wedding I used two shooters, three cameras and lenses from 16mm to 300mm. All f2.8 constant aperture, I might add.
Some people use an iphone and they think it is good!
I wasn't comparing the 24-105 to another single lens, but rather to a two-lens pair that might exceed the OP's self-described tight budget and might be more cumbersome to use.
I too don't see a price advantage to the 24-105 f/4L, relative to the Mark II version, and I don't quite know what to make of it. It must mean either that the Mark II is a real bargain or that it isn't as much better as its original hype suggested. I tend to suspect the latter, because the last time I looked, the price of the Mark I had stayed about the same, while that of the Mark II seemed to have fallen dramatically. The Mark II is bigger and heavier; so if it isn't significantly better, why would anyone prefer it?
".. if it isn't significantly better, why would anyone prefer it?"
Ah, because they don't make the first version any longer.
It was possible to get the original for around $500-600 bucks. At that price or even near it it was a no brainer. That's why I had two of them.
The new crop of f2.8L lense are so vastly superior. I have abandoned all but the trio I listed above ... somewhere. I wish I had them all along. 
@ebiggs1 wrote:".. if it isn't significantly better, why would anyone prefer it?"
Ah, because they don't make the first version any longer.
It was possible to get the original for around $500-600 bucks. At that price or even near it it was a no brainer. That's why I had two of them.
The new crop of f2.8L lense are so vastly superior. I have abandoned all but the trio I listed above ... somewhere. I wish I had them all along.
It's all a matter of whether the glass is half empty or half full, Ernie. Sure we wish that today's equipment had been available 50 years ago, but at least we two old geezers have lived to see it. Consider the plight of, say, Ansel Adams. He missed the digital age entirely (unless you consider late Polaroids to be a precursor), and one can only imagine how he would have loved Photoshop.
