70-200mm f/2.8 or not?

After selling the Nikkor 80-200mm f/2.8 that I purchased just one weekend ago, I was on the search for a Nikkor 70-200mm f/2.8.  The VR I and VR II versions are superb lenses from what I have read, but definitely not for the hobbyist like myself.  I cannot justify to spend $2200 on a lens that I will use a few times a year (the VR I lens might go for $1600 but I cannot find it anywhere, new.)  I then started looking at the Sigma alternative, the new 70-200mm OS.  New, that costs about $1500.  Not cheap.  So then I started looking at the Sigma 70-200mm Macro II (without OS).  I can purchase a used copy for $730 or so today, but should I?

Last night, I was at one of my nieces' birthday party and decided to bring just the Nikkor 50mm f/1.4D lens.  I figured my brothers would bring their DSLRs along so there is no need for a flash unit or the Tamron 17-50mm f/2.8 DC lens.  Well, the Nikkor 50mm is more like a 75mm in DX format.  I had difficulties using it.

For portraits, I could stand about a metre away from the subject and get a nice head shot.  A couple of metres away, I could take a fuller body.  A few metres more away, I could compose a scene with maybe five people in it but that was about it.  I did not have the luxury of the longer length of the room to shoot.  The Tamron 17-50mm would have worked much better than the 50mm.

What does it then mean for the 70-200mm lens (i.e. 105-300mm in DX format)?  If I was having so much problems with the 50mm, a 70mm will be a lot tougher to work with in an indoor environment.  A studio environment would be fine for it but not in an indoor party environment where you have little space and little control of the setup.  Therefore, a 70-200mm is pretty useless to me, indoors--it could work for wedding banquets though.  Having said that, I could use the 200mm focal length for outdoors photography or for sports events.  I thought I could use an f/2.8 aperture for a faster shutter speed to capture flitting hummingbirds, but if I really want a nice shot, I will have to use a fairly large depth of field and will have to use a flash gun too, so f/2.8 will not be useful in that scenario.

Therefore, I am going to purge this itch to purchase a 70-200mm lens for now.  If I have a wedding to shoot or get invited to a sports event, I will get one then.