Upload & Sell: Off
Thank you for your advice.I agree completely and I would love to have the 70-200 f2.8 VRII, but cost is one of the factors (I cannot justify (unless I win the lottery) the $2,400.00 price. While the $1200--$1500 range is not cheap either, it is more palatable, which was why I was considering either a non-Nikon f2.8, but people have said that they are neither as sharp nor focus as fast; or the VRI but have been read it does not focus as fast as the VRII or the f4) and size is another factor, (with many commenters saying the...Show more →
In your situation, there is no need to consider the VRII. It is a little smaller than the VRI -- and perhaps the focus is a little faster, but for the age group you are shooting, you won't ever know the difference. As for the costs, you will see the VRII lens selling used for $1800-$2000 -- and I agree that's overkill for your needs. The VRI version is widely available in the $1200-$1500 range -- and I seriously doubt you will see ANY difference between the VRI and VRII for your usage. The third party 70-200 2.8 lenses (most notably Tamron & Sigma) are significantly less money (i.e. $500-$700) but it is here that you will see a huge drop off in the image quality, focus speed, contrast, etc.
Here's another option. It's what I did as I was building my kit. I purchased a used Nikon 80-200 f/2.8 AF-D. There are three versions of the lens.
1) The old push-pull version
2) The AF-D
3) The AF-S
I never owned the push-pull because I don't like that zoom mechanism. The AF-S is supposed to focus a bit more quickly and will work on lower end Nikon cameras, but it is notorious for the focus motor squeak (and ultimately failure resulting in an expensive fix.) The good news is your D7100 has a built in focus motor which means you will have not problem using the AF-D version of the lens. You can find it for sale in the $600-$750 range. It does not have Vibration Reduction, and you lose 10 mm at the short end at the zoom range but it is a major upgrade over the third party options and will save some $$$$ over Nikon's 70-200 optioins.
To summarize, I would argue your best long-term bet is a used Nikon 70-200 VRI. A lower priced back-up plan would be to find a nice clean used 80-200 AF-D. If you have any more questions shoot me a PM, and I'd be happy to help answer questions.