I just ordered her from Sideshow, but mainly because I now have a decent pile of reward points. I plan on doing the same with Quicksilver. Granted, it's annoying to waste 200 points on the pack out charge, but it would be worse to abandon the reward points entirely. I have been using AE as my other principle supplier, plus I'm giving Pop Culture Zone a try for one figure. They require 20% down+shipping up front, but their prices are quite good and they also double box. If they turn out to be reliable, that's one more option for spreading out the cost of these figures. Given how many of these are due around the same time holiday bills will be arriving, that's a consideration for me.
BTW, when did you receive BW and WS from Alter Ego? They double boxed mine, but that was back in October/November. I'm getting the Groot/Rocket combo and AoU Cap from them. I'll be PO'd if they're not double boxed.