My intent is to have a couple of separate themed displays, and not really add to my Avengers group now that I have the six. That said, the one AoU figure I very nearly added was Scarlet Witch, so I could be pulled towards a future release of her. And likewise, Black Widow just does not have that 'perfect' representation yet that Captain America and Iron Man have with their AoU figures. I prefer the TWS look, but the AoU figure is probably better overall... maybe they will knock Civil War out of the park and tempt me.
I'll never see the need to add another Cap. I just don't want to spend the money on another IM unless it is VI or VII. Hawkeye I have my figure... and if I was going to War Machine I'd either cough up for the remake of IM2 or get AoU while it is cheap... My bet is Civil War will probably be the most expensive WM to date, yet the most unappealing. The other characters I'm just not feeling it enough, or it is too early at this stage.
The next Thor movie will be the one to likely get my money from MCU..